Imported Upstream version 3.2.0upstream

43 files changed, 5228 insertions, 1336 deletions

diff --git a/ext/fts1/fts1.c b/ext/fts1/fts1.c
index d5429ff..482cf75 100644
--- a/ext/fts1/fts1.c
+++ b/ext/fts1/fts1.c
@@ -3335,8 +3335,11 @@ int sqlite3Fts1Init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(sqlite3 *db, char **pzErrMsg,
-                           const sqlite3_api_routines *pApi){
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts1_init(sqlite3 *db, char **pzErrMsg,
+                      const sqlite3_api_routines *pApi){
   SQLITE_EXTENSION_INIT2(pApi)
   return sqlite3Fts1Init(db);
 }
diff --git a/ext/fts1/fulltext.c b/ext/fts1/fulltext.c
index e6034ba..313ff30 100644
--- a/ext/fts1/fulltext.c
+++ b/ext/fts1/fulltext.c
@@ -852,8 +852,14 @@ static void fulltext_vtab_destroy(fulltext_vtab *v){
 ** argv[3] - tokenizer name (optional, a sensible default is provided)
 ** argv[4..] - passed to tokenizer (optional based on tokenizer)
 **/
-static int fulltextConnect(sqlite3 *db, void *pAux, int argc, char **argv,
-                           sqlite3_vtab **ppVTab){
+static int fulltextConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc,
+  const char * const *argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
   int rc;
   fulltext_vtab *v;
   sqlite3_tokenizer_module *m = NULL;
@@ -898,8 +904,14 @@ static int fulltextConnect(sqlite3 *db, void *pAux, int argc, char **argv,
   return SQLITE_OK;
 }
 
-static int fulltextCreate(sqlite3 *db, void *pAux, int argc, char **argv,
-                          sqlite3_vtab **ppVTab){
+static int fulltextCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc,
+  const char * const *argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
   int rc;
   assert( argc>=3 );
 
@@ -934,7 +946,7 @@ static int fulltextCreate(sqlite3 *db, void *pAux, int argc, char **argv,
     "create index %_index on %_term(term, first)");
   if( rc!=SQLITE_OK ) return rc;
 
-  return fulltextConnect(db, pAux, argc, argv, ppVTab);
+  return fulltextConnect(db, pAux, argc, argv, ppVTab, pzErr);
 }
 
 /* Decide how to handle an SQL query.
@@ -1488,8 +1500,11 @@ int fulltext_init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(sqlite3 *db, char **pzErrMsg,
-                           const sqlite3_api_routines *pApi){
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fulltext_init(sqlite3 *db, char **pzErrMsg,
+                          const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi)
  return fulltext_init(db);
 }
diff --git a/ext/fts2/fts2.c b/ext/fts2/fts2.c
index f008ce6..0405fb7 100644
--- a/ext/fts2/fts2.c
+++ b/ext/fts2/fts2.c
@@ -6844,7 +6844,10 @@ int sqlite3Fts2Init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts2_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/ext/fts2/fts2_hash.c b/ext/fts2/fts2_hash.c
index f22fcc9..3596dcf 100644
--- a/ext/fts2/fts2_hash.c
+++ b/ext/fts2/fts2_hash.c
@@ -30,6 +30,8 @@
 #include <string.h>
 
 #include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_hash.h"
 
 /*
diff --git a/ext/fts2/fts2_porter.c b/ext/fts2/fts2_porter.c
index 16620b9..881baf7 100644
--- a/ext/fts2/fts2_porter.c
+++ b/ext/fts2/fts2_porter.c
@@ -30,6 +30,9 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_tokenizer.h"
 
 /*
diff --git a/ext/fts2/fts2_tokenizer.c b/ext/fts2/fts2_tokenizer.c
index a93790c..a3d6a63 100644
--- a/ext/fts2/fts2_tokenizer.c
+++ b/ext/fts2/fts2_tokenizer.c
@@ -28,7 +28,7 @@
 
 #include "sqlite3.h"
 #include "sqlite3ext.h"
-SQLITE_EXTENSION_INIT1
+SQLITE_EXTENSION_INIT3
 
 #include "fts2_hash.h"
 #include "fts2_tokenizer.h"
diff --git a/ext/fts2/fts2_tokenizer1.c b/ext/fts2/fts2_tokenizer1.c
index 7e13366..fe4f9eb 100644
--- a/ext/fts2/fts2_tokenizer1.c
+++ b/ext/fts2/fts2_tokenizer1.c
@@ -30,6 +30,9 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_tokenizer.h"
 
 typedef struct simple_tokenizer {
diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
index c00a13f..4f4b667 100644
--- a/ext/fts3/fts3.c
+++ b/ext/fts3/fts3.c
@@ -330,21 +330,37 @@ int sqlite3Fts3PutVarint(char *p, sqlite_int64 v){
   return (int) (q - (unsigned char *)p);
 }
 
+#define GETVARINT_STEP(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (v & mask1) | ( (*ptr++) << shift );                    \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+#define GETVARINT_INIT(v, ptr, shift, mask1, mask2, var, ret) \
+  v = (*ptr++);                                               \
+  if( (v & mask2)==0 ){ var = v; return ret; }
+
 /* 
 ** Read a 64-bit variable-length integer from memory starting at p[0].
 ** Return the number of bytes read, or 0 on error.
 ** The value is stored in *v.
 */
 int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
-  const unsigned char *q = (const unsigned char *) p;
-  sqlite_uint64 x = 0, y = 1;
-  while( (*q&0x80)==0x80 && q-(unsigned char *)p<FTS3_VARINT_MAX ){
-    x += y * (*q++ & 0x7f);
-    y <<= 7;
-  }
-  x += y * (*q++);
-  *v = (sqlite_int64) x;
-  return (int) (q - (unsigned char *)p);
+  const char *pStart = p;
+  u32 a;
+  u64 b;
+  int shift;
+
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *v, 1);
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *v, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *v, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *v, 4);
+  b = (a & 0x0FFFFFFF );
+
+  for(shift=28; shift<=63; shift+=7){
+    u64 c = *p++;
+    b += (c&0x7F) << shift;
+    if( (c & 0x80)==0 ) break;
+  }
+  *v = b;
+  return (int)(p - pStart);
 }
 
 /*
@@ -352,10 +368,21 @@ int sqlite3Fts3GetVarint(const char *p, sqlite_int64 *v){
 ** 32-bit integer before it is returned.
 */
 int sqlite3Fts3GetVarint32(const char *p, int *pi){
- sqlite_int64 i;
- int ret = sqlite3Fts3GetVarint(p, &i);
- *pi = (int) i;
- return ret;
+  u32 a;
+
+#ifndef fts3GetVarint32
+  GETVARINT_INIT(a, p, 0,  0x00,     0x80, *pi, 1);
+#else
+  a = (*p++);
+  assert( a & 0x80 );
+#endif
+
+  GETVARINT_STEP(a, p, 7,  0x7F,     0x4000, *pi, 2);
+  GETVARINT_STEP(a, p, 14, 0x3FFF,   0x200000, *pi, 3);
+  GETVARINT_STEP(a, p, 21, 0x1FFFFF, 0x10000000, *pi, 4);
+  a = (a & 0x0FFFFFFF );
+  *pi = (int)(a | ((u32)(*p & 0x0F) << 28));
+  return 5;
 }
 
 /*
@@ -1081,6 +1108,8 @@ static int fts3InitVtab(
   char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
   char *zContent = 0;             /* content=? parameter (or NULL) */
   char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */
+  char **azNotindexed = 0;        /* The set of notindexed= columns */
+  int nNotindexed = 0;            /* Size of azNotindexed[] array */
 
   assert( strlen(argv[0])==4 );
   assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
@@ -1090,9 +1119,19 @@ static int fts3InitVtab(
   nDb = (int)strlen(argv[1]) + 1;
   nName = (int)strlen(argv[2]) + 1;
 
-  aCol = (const char **)sqlite3_malloc(sizeof(const char *) * (argc-2) );
-  if( !aCol ) return SQLITE_NOMEM;
-  memset((void *)aCol, 0, sizeof(const char *) * (argc-2));
+  nByte = sizeof(const char *) * (argc-2);
+  aCol = (const char **)sqlite3_malloc(nByte);
+  if( aCol ){
+    memset((void*)aCol, 0, nByte);
+    azNotindexed = (char **)sqlite3_malloc(nByte);
+  }
+  if( azNotindexed ){
+    memset(azNotindexed, 0, nByte);
+  }
+  if( !aCol || !azNotindexed ){
+    rc = SQLITE_NOMEM;
+    goto fts3_init_out;
+  }
 
   /* Loop through all of the arguments passed by the user to the FTS3/4
   ** module (i.e. all the column names and special arguments). This loop
@@ -1131,7 +1170,8 @@ static int fts3InitVtab(
         { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
         { "order",       5 },     /* 4 -> ORDER */
         { "content",     7 },     /* 5 -> CONTENT */
-        { "languageid", 10 }      /* 6 -> LANGUAGEID */
+        { "languageid", 10 },     /* 6 -> LANGUAGEID */
+        { "notindexed", 10 }      /* 7 -> NOTINDEXED */
       };
 
       int iOpt;
@@ -1197,6 +1237,11 @@ static int fts3InitVtab(
               zLanguageid = zVal;
               zVal = 0;
               break;
+
+            case 7:              /* NOTINDEXED */
+              azNotindexed[nNotindexed++] = zVal;
+              zVal = 0;
+              break;
           }
         }
         sqlite3_free(zVal);
@@ -1268,6 +1313,7 @@ static int fts3InitVtab(
   nByte = sizeof(Fts3Table) +                  /* Fts3Table */
           nCol * sizeof(char *) +              /* azColumn */
           nIndex * sizeof(struct Fts3Index) +  /* aIndex */
+          nCol * sizeof(u8) +                  /* abNotindexed */
           nName +                              /* zName */
           nDb +                                /* zDb */
           nString;                             /* Space for azColumn strings */
@@ -1287,7 +1333,7 @@ static int fts3InitVtab(
   p->bHasStat = isFts4;
   p->bFts4 = isFts4;
   p->bDescIdx = bDescIdx;
-  p->bAutoincrmerge = 0xff;   /* 0xff means setting unknown */
+  p->nAutoincrmerge = 0xff;   /* 0xff means setting unknown */
   p->zContentTbl = zContent;
   p->zLanguageid = zLanguageid;
   zContent = 0;
@@ -1301,9 +1347,10 @@ static int fts3InitVtab(
   for(i=0; i<nIndex; i++){
     fts3HashInit(&p->aIndex[i].hPending, FTS3_HASH_STRING, 1);
   }
+  p->abNotindexed = (u8 *)&p->aIndex[nIndex];
 
   /* Fill in the zName and zDb fields of the vtab structure. */
-  zCsr = (char *)&p->aIndex[nIndex];
+  zCsr = (char *)&p->abNotindexed[nCol];
   p->zName = zCsr;
   memcpy(zCsr, argv[2], nName);
   zCsr += nName;
@@ -1324,7 +1371,28 @@ static int fts3InitVtab(
     assert( zCsr <= &((char *)p)[nByte] );
   }
 
-  if( (zCompress==0)!=(zUncompress==0) ){
+  /* Fill in the abNotindexed array */
+  for(iCol=0; iCol<nCol; iCol++){
+    int n = (int)strlen(p->azColumn[iCol]);
+    for(i=0; i<nNotindexed; i++){
+      char *zNot = azNotindexed[i];
+      if( zNot && n==(int)strlen(zNot)
+       && 0==sqlite3_strnicmp(p->azColumn[iCol], zNot, n) 
+      ){
+        p->abNotindexed[iCol] = 1;
+        sqlite3_free(zNot);
+        azNotindexed[i] = 0;
+      }
+    }
+  }
+  for(i=0; i<nNotindexed; i++){
+    if( azNotindexed[i] ){
+      *pzErr = sqlite3_mprintf("no such column: %s", azNotindexed[i]);
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){
     char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
     rc = SQLITE_ERROR;
     *pzErr = sqlite3_mprintf("missing %s parameter in fts4 constructor", zMiss);
@@ -1344,10 +1412,7 @@ static int fts3InitVtab(
   ** addition of a %_stat table so that it can use incremental merge.
   */
   if( !isFts4 && !isCreate ){
-    int rc2 = SQLITE_OK;
-    fts3DbExec(&rc2, db, "SELECT 1 FROM %Q.'%q_stat' WHERE id=2",
-               p->zDb, p->zName);
-    if( rc2==SQLITE_OK ) p->bHasStat = 1;
+    p->bHasStat = 2;
   }
 
   /* Figure out the page-size for the database. This is required in order to
@@ -1365,7 +1430,9 @@ fts3_init_out:
   sqlite3_free(zUncompress);
   sqlite3_free(zContent);
   sqlite3_free(zLanguageid);
+  for(i=0; i<nNotindexed; i++) sqlite3_free(azNotindexed[i]);
   sqlite3_free((void *)aCol);
+  sqlite3_free((void *)azNotindexed);
   if( rc!=SQLITE_OK ){
     if( p ){
       fts3DisconnectMethod((sqlite3_vtab *)p);
@@ -1404,6 +1471,19 @@ static int fts3CreateMethod(
   return fts3InitVtab(1, db, pAux, argc, argv, ppVtab, pzErr);
 }
 
+/*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void fts3SetEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+  if( sqlite3_libversion_number()>=3008002 ){
+    pIdxInfo->estimatedRows = nRow;
+  }
+#endif
+}
+
 /* 
 ** Implementation of the xBestIndex method for FTS3 tables. There
 ** are three possible strategies, in order of preference:
@@ -1416,23 +1496,40 @@ static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
   Fts3Table *p = (Fts3Table *)pVTab;
   int i;                          /* Iterator variable */
   int iCons = -1;                 /* Index of constraint to use */
+
   int iLangidCons = -1;           /* Index of langid=x constraint, if present */
+  int iDocidGe = -1;              /* Index of docid>=x constraint, if present */
+  int iDocidLe = -1;              /* Index of docid<=x constraint, if present */
+  int iIdx;
 
   /* By default use a full table scan. This is an expensive option,
   ** so search through the constraints to see if a more efficient 
   ** strategy is possible.
   */
   pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
-  pInfo->estimatedCost = 500000;
+  pInfo->estimatedCost = 5000000;
   for(i=0; i<pInfo->nConstraint; i++){
+    int bDocid;                 /* True if this constraint is on docid */
     struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
-    if( pCons->usable==0 ) continue;
+    if( pCons->usable==0 ){
+      if( pCons->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+        /* There exists an unusable MATCH constraint. This means that if
+        ** the planner does elect to use the results of this call as part
+        ** of the overall query plan the user will see an "unable to use
+        ** function MATCH in the requested context" error. To discourage
+        ** this, return a very high cost here.  */
+        pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
+        pInfo->estimatedCost = 1e50;
+        fts3SetEstimatedRows(pInfo, ((sqlite3_int64)1) << 50);
+        return SQLITE_OK;
+      }
+      continue;
+    }
+
+    bDocid = (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1);
 
     /* A direct lookup on the rowid or docid column. Assign a cost of 1.0. */
-    if( iCons<0 
-     && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ 
-     && (pCons->iColumn<0 || pCons->iColumn==p->nColumn+1 )
-    ){
+    if( iCons<0 && pCons->op==SQLITE_INDEX_CONSTRAINT_EQ && bDocid ){
       pInfo->idxNum = FTS3_DOCID_SEARCH;
       pInfo->estimatedCost = 1.0;
       iCons = i;
@@ -1461,14 +1558,38 @@ static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
     ){
       iLangidCons = i;
     }
+
+    if( bDocid ){
+      switch( pCons->op ){
+        case SQLITE_INDEX_CONSTRAINT_GE:
+        case SQLITE_INDEX_CONSTRAINT_GT:
+          iDocidGe = i;
+          break;
+
+        case SQLITE_INDEX_CONSTRAINT_LE:
+        case SQLITE_INDEX_CONSTRAINT_LT:
+          iDocidLe = i;
+          break;
+      }
+    }
   }
 
+  iIdx = 1;
   if( iCons>=0 ){
-    pInfo->aConstraintUsage[iCons].argvIndex = 1;
+    pInfo->aConstraintUsage[iCons].argvIndex = iIdx++;
     pInfo->aConstraintUsage[iCons].omit = 1;
   } 
   if( iLangidCons>=0 ){
-    pInfo->aConstraintUsage[iLangidCons].argvIndex = 2;
+    pInfo->idxNum |= FTS3_HAVE_LANGID;
+    pInfo->aConstraintUsage[iLangidCons].argvIndex = iIdx++;
+  } 
+  if( iDocidGe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_GE;
+    pInfo->aConstraintUsage[iDocidGe].argvIndex = iIdx++;
+  } 
+  if( iDocidLe>=0 ){
+    pInfo->idxNum |= FTS3_HAVE_DOCID_LE;
+    pInfo->aConstraintUsage[iDocidLe].argvIndex = iIdx++;
   } 
 
   /* Regardless of the strategy selected, FTS can deliver rows in rowid (or
@@ -1646,10 +1767,10 @@ static int fts3ScanInteriorNode(
     /* Load the next term on the node into zBuffer. Use realloc() to expand
     ** the size of zBuffer if required.  */
     if( !isFirstTerm ){
-      zCsr += sqlite3Fts3GetVarint32(zCsr, &nPrefix);
+      zCsr += fts3GetVarint32(zCsr, &nPrefix);
     }
     isFirstTerm = 0;
-    zCsr += sqlite3Fts3GetVarint32(zCsr, &nSuffix);
+    zCsr += fts3GetVarint32(zCsr, &nSuffix);
     
     if( nPrefix<0 || nSuffix<0 || &zCsr[nSuffix]>zEnd ){
       rc = FTS_CORRUPT_VTAB;
@@ -1737,7 +1858,7 @@ static int fts3SelectLeaf(
 
   assert( piLeaf || piLeaf2 );
 
-  sqlite3Fts3GetVarint32(zNode, &iHeight);
+  fts3GetVarint32(zNode, &iHeight);
   rc = fts3ScanInteriorNode(zTerm, nTerm, zNode, nNode, piLeaf, piLeaf2);
   assert( !piLeaf2 || !piLeaf || rc!=SQLITE_OK || (*piLeaf<=*piLeaf2) );
 
@@ -1939,11 +2060,11 @@ static void fts3PoslistMerge(
     int iCol1;         /* The current column index in pp1 */
     int iCol2;         /* The current column index in pp2 */
 
-    if( *p1==POS_COLUMN ) sqlite3Fts3GetVarint32(&p1[1], &iCol1);
+    if( *p1==POS_COLUMN ) fts3GetVarint32(&p1[1], &iCol1);
     else if( *p1==POS_END ) iCol1 = POSITION_LIST_END;
     else iCol1 = 0;
 
-    if( *p2==POS_COLUMN ) sqlite3Fts3GetVarint32(&p2[1], &iCol2);
+    if( *p2==POS_COLUMN ) fts3GetVarint32(&p2[1], &iCol2);
     else if( *p2==POS_END ) iCol2 = POSITION_LIST_END;
     else iCol2 = 0;
 
@@ -2036,11 +2157,11 @@ static int fts3PoslistPhraseMerge(
   assert( p!=0 && *p1!=0 && *p2!=0 );
   if( *p1==POS_COLUMN ){ 
     p1++;
-    p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+    p1 += fts3GetVarint32(p1, &iCol1);
   }
   if( *p2==POS_COLUMN ){ 
     p2++;
-    p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+    p2 += fts3GetVarint32(p2, &iCol2);
   }
 
   while( 1 ){
@@ -2090,9 +2211,9 @@ static int fts3PoslistPhraseMerge(
       if( 0==*p1 || 0==*p2 ) break;
 
       p1++;
-      p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+      p1 += fts3GetVarint32(p1, &iCol1);
       p2++;
-      p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+      p2 += fts3GetVarint32(p2, &iCol2);
     }
 
     /* Advance pointer p1 or p2 (whichever corresponds to the smaller of
@@ -2104,12 +2225,12 @@ static int fts3PoslistPhraseMerge(
       fts3ColumnlistCopy(0, &p1);
       if( 0==*p1 ) break;
       p1++;
-      p1 += sqlite3Fts3GetVarint32(p1, &iCol1);
+      p1 += fts3GetVarint32(p1, &iCol1);
     }else{
       fts3ColumnlistCopy(0, &p2);
       if( 0==*p2 ) break;
       p2++;
-      p2 += sqlite3Fts3GetVarint32(p2, &iCol2);
+      p2 += fts3GetVarint32(p2, &iCol2);
     }
   }
 
@@ -2916,6 +3037,33 @@ static int fts3NextMethod(sqlite3_vtab_cursor *pCursor){
 }
 
 /*
+** The following are copied from sqliteInt.h.
+**
+** Constants for the largest and smallest possible 64-bit signed integers.
+** These macros are designed to work correctly on both 32-bit and 64-bit
+** compilers.
+*/
+#ifndef SQLITE_AMALGAMATION
+# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
+# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
+#endif
+
+/*
+** If the numeric type of argument pVal is "integer", then return it
+** converted to a 64-bit signed integer. Otherwise, return a copy of
+** the second parameter, iDefault.
+*/
+static sqlite3_int64 fts3DocidRange(sqlite3_value *pVal, i64 iDefault){
+  if( pVal ){
+    int eType = sqlite3_value_numeric_type(pVal);
+    if( eType==SQLITE_INTEGER ){
+      return sqlite3_value_int64(pVal);
+    }
+  }
+  return iDefault;
+}
+
+/*
 ** This is the xFilter interface for the virtual table.  See
 ** the virtual table xFilter method documentation for additional
 ** information.
@@ -2940,40 +3088,58 @@ static int fts3FilterMethod(
 ){
   int rc;
   char *zSql;                     /* SQL statement used to access %_content */
+  int eSearch;
   Fts3Table *p = (Fts3Table *)pCursor->pVtab;
   Fts3Cursor *pCsr = (Fts3Cursor *)pCursor;
 
+  sqlite3_value *pCons = 0;       /* The MATCH or rowid constraint, if any */
+  sqlite3_value *pLangid = 0;     /* The "langid = ?" constraint, if any */
+  sqlite3_value *pDocidGe = 0;    /* The "docid >= ?" constraint, if any */
+  sqlite3_value *pDocidLe = 0;    /* The "docid <= ?" constraint, if any */
+  int iIdx;
+
   UNUSED_PARAMETER(idxStr);
   UNUSED_PARAMETER(nVal);
 
-  assert( idxNum>=0 && idxNum<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
-  assert( nVal==0 || nVal==1 || nVal==2 );
-  assert( (nVal==0)==(idxNum==FTS3_FULLSCAN_SEARCH) );
+  eSearch = (idxNum & 0x0000FFFF);
+  assert( eSearch>=0 && eSearch<=(FTS3_FULLTEXT_SEARCH+p->nColumn) );
   assert( p->pSegments==0 );
 
+  /* Collect arguments into local variables */
+  iIdx = 0;
+  if( eSearch!=FTS3_FULLSCAN_SEARCH ) pCons = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_LANGID ) pLangid = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_GE ) pDocidGe = apVal[iIdx++];
+  if( idxNum & FTS3_HAVE_DOCID_LE ) pDocidLe = apVal[iIdx++];
+  assert( iIdx==nVal );
+
   /* In case the cursor has been used before, clear it now. */
   sqlite3_finalize(pCsr->pStmt);
   sqlite3_free(pCsr->aDoclist);
   sqlite3Fts3ExprFree(pCsr->pExpr);
   memset(&pCursor[1], 0, sizeof(Fts3Cursor)-sizeof(sqlite3_vtab_cursor));
 
+  /* Set the lower and upper bounds on docids to return */
+  pCsr->iMinDocid = fts3DocidRange(pDocidGe, SMALLEST_INT64);
+  pCsr->iMaxDocid = fts3DocidRange(pDocidLe, LARGEST_INT64);
+
   if( idxStr ){
     pCsr->bDesc = (idxStr[0]=='D');
   }else{
     pCsr->bDesc = p->bDescIdx;
   }
-  pCsr->eSearch = (i16)idxNum;
+  pCsr->eSearch = (i16)eSearch;
 
-  if( idxNum!=FTS3_DOCID_SEARCH && idxNum!=FTS3_FULLSCAN_SEARCH ){
-    int iCol = idxNum-FTS3_FULLTEXT_SEARCH;
-    const char *zQuery = (const char *)sqlite3_value_text(apVal[0]);
+  if( eSearch!=FTS3_DOCID_SEARCH && eSearch!=FTS3_FULLSCAN_SEARCH ){
+    int iCol = eSearch-FTS3_FULLTEXT_SEARCH;
+    const char *zQuery = (const char *)sqlite3_value_text(pCons);
 
-    if( zQuery==0 && sqlite3_value_type(apVal[0])!=SQLITE_NULL ){
+    if( zQuery==0 && sqlite3_value_type(pCons)!=SQLITE_NULL ){
       return SQLITE_NOMEM;
     }
 
     pCsr->iLangid = 0;
-    if( nVal==2 ) pCsr->iLangid = sqlite3_value_int(apVal[1]);
+    if( pLangid ) pCsr->iLangid = sqlite3_value_int(pLangid);
 
     assert( p->base.zErrMsg==0 );
     rc = sqlite3Fts3ExprParse(p->pTokenizer, pCsr->iLangid,
@@ -2984,11 +3150,7 @@ static int fts3FilterMethod(
       return rc;
     }
 
-    rc = sqlite3Fts3ReadLock(p);
-    if( rc!=SQLITE_OK ) return rc;
-
     rc = fts3EvalStart(pCsr);
-
     sqlite3Fts3SegmentsClose(p);
     if( rc!=SQLITE_OK ) return rc;
     pCsr->pNextId = pCsr->aDoclist;
@@ -3000,7 +3162,7 @@ static int fts3FilterMethod(
   ** full-text query or docid lookup, the statement retrieves a single
   ** row by docid.
   */
-  if( idxNum==FTS3_FULLSCAN_SEARCH ){
+  if( eSearch==FTS3_FULLSCAN_SEARCH ){
     zSql = sqlite3_mprintf(
         "SELECT %s ORDER BY rowid %s",
         p->zReadExprlist, (pCsr->bDesc ? "DESC" : "ASC")
@@ -3011,10 +3173,10 @@ static int fts3FilterMethod(
     }else{
       rc = SQLITE_NOMEM;
     }
-  }else if( idxNum==FTS3_DOCID_SEARCH ){
+  }else if( eSearch==FTS3_DOCID_SEARCH ){
     rc = fts3CursorSeekStmt(pCsr, &pCsr->pStmt);
     if( rc==SQLITE_OK ){
-      rc = sqlite3_bind_value(pCsr->pStmt, 1, apVal[0]);
+      rc = sqlite3_bind_value(pCsr->pStmt, 1, pCons);
     }
   }
   if( rc!=SQLITE_OK ) return rc;
@@ -3142,7 +3304,10 @@ static int fts3SyncMethod(sqlite3_vtab *pVtab){
   Fts3Table *p = (Fts3Table*)pVtab;
   int rc = sqlite3Fts3PendingTermsFlush(p);
 
-  if( rc==SQLITE_OK && p->bAutoincrmerge==1 && p->nLeafAdd>(nMinMerge/16) ){
+  if( rc==SQLITE_OK 
+   && p->nLeafAdd>(nMinMerge/16) 
+   && p->nAutoincrmerge && p->nAutoincrmerge!=0xff
+  ){
     int mxLevel = 0;              /* Maximum relative level value in db */
     int A;                        /* Incr-merge parameter A */
 
@@ -3150,14 +3315,41 @@ static int fts3SyncMethod(sqlite3_vtab *pVtab){
     assert( rc==SQLITE_OK || mxLevel==0 );
     A = p->nLeafAdd * mxLevel;
     A += (A/2);
-    if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, 8);
+    if( A>(int)nMinMerge ) rc = sqlite3Fts3Incrmerge(p, A, p->nAutoincrmerge);
   }
   sqlite3Fts3SegmentsClose(p);
   return rc;
 }
 
 /*
-** Implementation of xBegin() method. This is a no-op.
+** If it is currently unknown whether or not the FTS table has an %_stat
+** table (if p->bHasStat==2), attempt to determine this (set p->bHasStat
+** to 0 or 1). Return SQLITE_OK if successful, or an SQLite error code
+** if an error occurs.
+*/
+static int fts3SetHasStat(Fts3Table *p){
+  int rc = SQLITE_OK;
+  if( p->bHasStat==2 ){
+    const char *zFmt ="SELECT 1 FROM %Q.sqlite_master WHERE tbl_name='%q_stat'";
+    char *zSql = sqlite3_mprintf(zFmt, p->zDb, p->zName);
+    if( zSql ){
+      sqlite3_stmt *pStmt = 0;
+      rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0);
+      if( rc==SQLITE_OK ){
+        int bHasStat = (sqlite3_step(pStmt)==SQLITE_ROW);
+        rc = sqlite3_finalize(pStmt);
+        if( rc==SQLITE_OK ) p->bHasStat = bHasStat;
+      }
+      sqlite3_free(zSql);
+    }else{
+      rc = SQLITE_NOMEM;
+    }
+  }
+  return rc;
+}
+
+/*
+** Implementation of xBegin() method. 
 */
 static int fts3BeginMethod(sqlite3_vtab *pVtab){
   Fts3Table *p = (Fts3Table*)pVtab;
@@ -3168,7 +3360,7 @@ static int fts3BeginMethod(sqlite3_vtab *pVtab){
   TESTONLY( p->inTransaction = 1 );
   TESTONLY( p->mxSavepoint = -1; );
   p->nLeafAdd = 0;
-  return SQLITE_OK;
+  return fts3SetHasStat(p);
 }
 
 /*
@@ -3417,6 +3609,10 @@ static int fts3RenameMethod(
   sqlite3 *db = p->db;            /* Database connection */
   int rc;                         /* Return Code */
 
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  rc = fts3SetHasStat(p);
+  
   /* As it happens, the pending terms table is always empty here. This is
   ** because an "ALTER TABLE RENAME TABLE" statement inside a transaction 
   ** always opens a savepoint transaction. And the xSavepoint() method 
@@ -3424,7 +3620,9 @@ static int fts3RenameMethod(
   ** PendingTermsFlush() in in case that changes.
   */
   assert( p->nPendingData==0 );
-  rc = sqlite3Fts3PendingTermsFlush(p);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3Fts3PendingTermsFlush(p);
+  }
 
   if( p->zContentTbl==0 ){
     fts3DbExec(&rc, db,
@@ -3552,7 +3750,7 @@ static void hashDestroy(void *p){
 */
 void sqlite3Fts3SimpleTokenizerModule(sqlite3_tokenizer_module const**ppModule);
 void sqlite3Fts3PorterTokenizerModule(sqlite3_tokenizer_module const**ppModule);
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
 void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const**ppModule);
 #endif
 #ifdef SQLITE_ENABLE_ICU
@@ -3570,7 +3768,7 @@ int sqlite3Fts3Init(sqlite3 *db){
   Fts3Hash *pHash = 0;
   const sqlite3_tokenizer_module *pSimple = 0;
   const sqlite3_tokenizer_module *pPorter = 0;
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
   const sqlite3_tokenizer_module *pUnicode = 0;
 #endif
 
@@ -3579,7 +3777,7 @@ int sqlite3Fts3Init(sqlite3 *db){
   sqlite3Fts3IcuTokenizerModule(&pIcu);
 #endif
 
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
   sqlite3Fts3UnicodeTokenizer(&pUnicode);
 #endif
 
@@ -3607,7 +3805,7 @@ int sqlite3Fts3Init(sqlite3 *db){
     if( sqlite3Fts3HashInsert(pHash, "simple", 7, (void *)pSimple)
      || sqlite3Fts3HashInsert(pHash, "porter", 7, (void *)pPorter) 
 
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
      || sqlite3Fts3HashInsert(pHash, "unicode61", 10, (void *)pUnicode) 
 #endif
 #ifdef SQLITE_ENABLE_ICU
@@ -3906,6 +4104,12 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
 }
 
 /*
+** Maximum number of tokens a phrase may have to be considered for the
+** incremental doclists strategy.
+*/
+#define MAX_INCR_PHRASE_TOKENS 4
+
+/*
 ** This function is called for each Fts3Phrase in a full-text query 
 ** expression to initialize the mechanism for returning rows. Once this
 ** function has been called successfully on an Fts3Phrase, it may be
@@ -3918,23 +4122,43 @@ static int fts3EvalDeferredPhrase(Fts3Cursor *pCsr, Fts3Phrase *pPhrase){
 ** SQLITE_OK is returned if no error occurs, otherwise an SQLite error code.
 */
 static int fts3EvalPhraseStart(Fts3Cursor *pCsr, int bOptOk, Fts3Phrase *p){
-  int rc;                         /* Error code */
-  Fts3PhraseToken *pFirst = &p->aToken[0];
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  int rc = SQLITE_OK;             /* Error code */
+  int i;
 
-  if( pCsr->bDesc==pTab->bDescIdx 
-   && bOptOk==1 
-   && p->nToken==1 
-   && pFirst->pSegcsr 
-   && pFirst->pSegcsr->bLookup 
-   && pFirst->bFirst==0
-  ){
+  /* Determine if doclists may be loaded from disk incrementally. This is
+  ** possible if the bOptOk argument is true, the FTS doclists will be
+  ** scanned in forward order, and the phrase consists of 
+  ** MAX_INCR_PHRASE_TOKENS or fewer tokens, none of which are are "^first"
+  ** tokens or prefix tokens that cannot use a prefix-index.  */
+  int bHaveIncr = 0;
+  int bIncrOk = (bOptOk 
+   && pCsr->bDesc==pTab->bDescIdx 
+   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
+   && p->nToken<=MAX_INCR_PHRASE_TOKENS && p->nToken>0
+#ifdef SQLITE_TEST
+   && pTab->bNoIncrDoclist==0
+#endif
+  );
+  for(i=0; bIncrOk==1 && i<p->nToken; i++){
+    Fts3PhraseToken *pToken = &p->aToken[i];
+    if( pToken->bFirst || (pToken->pSegcsr!=0 && !pToken->pSegcsr->bLookup) ){
+      bIncrOk = 0;
+    }
+    if( pToken->pSegcsr ) bHaveIncr = 1;
+  }
+
+  if( bIncrOk && bHaveIncr ){
     /* Use the incremental approach. */
     int iCol = (p->iColumn >= pTab->nColumn ? -1 : p->iColumn);
-    rc = sqlite3Fts3MsrIncrStart(
-        pTab, pFirst->pSegcsr, iCol, pFirst->z, pFirst->n);
+    for(i=0; rc==SQLITE_OK && i<p->nToken; i++){
+      Fts3PhraseToken *pToken = &p->aToken[i];
+      Fts3MultiSegReader *pSegcsr = pToken->pSegcsr;
+      if( pSegcsr ){
+        rc = sqlite3Fts3MsrIncrStart(pTab, pSegcsr, iCol, pToken->z, pToken->n);
+      }
+    }
     p->bIncr = 1;
-
   }else{
     /* Load the full doclist for the phrase into memory. */
     rc = fts3EvalPhraseLoad(pCsr, p);
@@ -4044,15 +4268,125 @@ void sqlite3Fts3DoclistNext(
 }
 
 /*
-** Attempt to move the phrase iterator to point to the next matching docid. 
+** Advance the iterator pDL to the next entry in pDL->aAll/nAll. Set *pbEof
+** to true if EOF is reached.
+*/
+static void fts3EvalDlPhraseNext(
+  Fts3Table *pTab,
+  Fts3Doclist *pDL,
+  u8 *pbEof
+){
+  char *pIter;                            /* Used to iterate through aAll */
+  char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
+ 
+  if( pDL->pNextDocid ){
+    pIter = pDL->pNextDocid;
+  }else{
+    pIter = pDL->aAll;
+  }
+
+  if( pIter>=pEnd ){
+    /* We have already reached the end of this doclist. EOF. */
+    *pbEof = 1;
+  }else{
+    sqlite3_int64 iDelta;
+    pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
+    if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
+      pDL->iDocid += iDelta;
+    }else{
+      pDL->iDocid -= iDelta;
+    }
+    pDL->pList = pIter;
+    fts3PoslistCopy(0, &pIter);
+    pDL->nList = (int)(pIter - pDL->pList);
+
+    /* pIter now points just past the 0x00 that terminates the position-
+    ** list for document pDL->iDocid. However, if this position-list was
+    ** edited in place by fts3EvalNearTrim(), then pIter may not actually
+    ** point to the start of the next docid value. The following line deals
+    ** with this case by advancing pIter past the zero-padding added by
+    ** fts3EvalNearTrim().  */
+    while( pIter<pEnd && *pIter==0 ) pIter++;
+
+    pDL->pNextDocid = pIter;
+    assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
+    *pbEof = 0;
+  }
+}
+
+/*
+** Helper type used by fts3EvalIncrPhraseNext() and incrPhraseTokenNext().
+*/
+typedef struct TokenDoclist TokenDoclist;
+struct TokenDoclist {
+  int bIgnore;
+  sqlite3_int64 iDocid;
+  char *pList;
+  int nList;
+};
+
+/*
+** Token pToken is an incrementally loaded token that is part of a 
+** multi-token phrase. Advance it to the next matching document in the
+** database and populate output variable *p with the details of the new
+** entry. Or, if the iterator has reached EOF, set *pbEof to true.
+**
 ** If an error occurs, return an SQLite error code. Otherwise, return 
 ** SQLITE_OK.
+*/
+static int incrPhraseTokenNext(
+  Fts3Table *pTab,                /* Virtual table handle */
+  Fts3Phrase *pPhrase,            /* Phrase to advance token of */
+  int iToken,                     /* Specific token to advance */
+  TokenDoclist *p,                /* OUT: Docid and doclist for new entry */
+  u8 *pbEof                       /* OUT: True if iterator is at EOF */
+){
+  int rc = SQLITE_OK;
+
+  if( pPhrase->iDoclistToken==iToken ){
+    assert( p->bIgnore==0 );
+    assert( pPhrase->aToken[iToken].pSegcsr==0 );
+    fts3EvalDlPhraseNext(pTab, &pPhrase->doclist, pbEof);
+    p->pList = pPhrase->doclist.pList;
+    p->nList = pPhrase->doclist.nList;
+    p->iDocid = pPhrase->doclist.iDocid;
+  }else{
+    Fts3PhraseToken *pToken = &pPhrase->aToken[iToken];
+    assert( pToken->pDeferred==0 );
+    assert( pToken->pSegcsr || pPhrase->iDoclistToken>=0 );
+    if( pToken->pSegcsr ){
+      assert( p->bIgnore==0 );
+      rc = sqlite3Fts3MsrIncrNext(
+          pTab, pToken->pSegcsr, &p->iDocid, &p->pList, &p->nList
+      );
+      if( p->pList==0 ) *pbEof = 1;
+    }else{
+      p->bIgnore = 1;
+    }
+  }
+
+  return rc;
+}
+
+
+/*
+** The phrase iterator passed as the second argument:
+**
+**   * features at least one token that uses an incremental doclist, and 
+**
+**   * does not contain any deferred tokens.
+**
+** Advance it to the next matching documnent in the database and populate
+** the Fts3Doclist.pList and nList fields. 
 **
 ** If there is no "next" entry and no error occurs, then *pbEof is set to
 ** 1 before returning. Otherwise, if no error occurs and the iterator is
 ** successfully advanced, *pbEof is set to 0.
+**
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
 */
-static int fts3EvalPhraseNext(
+static int fts3EvalIncrPhraseNext(
   Fts3Cursor *pCsr,               /* FTS Cursor handle */
   Fts3Phrase *p,                  /* Phrase object to advance to next docid */
   u8 *pbEof                       /* OUT: Set to 1 if EOF */
@@ -4060,57 +4394,116 @@ static int fts3EvalPhraseNext(
   int rc = SQLITE_OK;
   Fts3Doclist *pDL = &p->doclist;
   Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+  u8 bEof = 0;
 
-  if( p->bIncr ){
-    assert( p->nToken==1 );
-    assert( pDL->pNextDocid==0 );
+  /* This is only called if it is guaranteed that the phrase has at least
+  ** one incremental token. In which case the bIncr flag is set. */
+  assert( p->bIncr==1 );
+
+  if( p->nToken==1 && p->bIncr ){
     rc = sqlite3Fts3MsrIncrNext(pTab, p->aToken[0].pSegcsr, 
         &pDL->iDocid, &pDL->pList, &pDL->nList
     );
-    if( rc==SQLITE_OK && !pDL->pList ){
-      *pbEof = 1;
+    if( pDL->pList==0 ) bEof = 1;
+  }else{
+    int bDescDoclist = pCsr->bDesc;
+    struct TokenDoclist a[MAX_INCR_PHRASE_TOKENS];
+
+    memset(a, 0, sizeof(a));
+    assert( p->nToken<=MAX_INCR_PHRASE_TOKENS );
+    assert( p->iDoclistToken<MAX_INCR_PHRASE_TOKENS );
+
+    while( bEof==0 ){
+      int bMaxSet = 0;
+      sqlite3_int64 iMax = 0;     /* Largest docid for all iterators */
+      int i;                      /* Used to iterate through tokens */
+
+      /* Advance the iterator for each token in the phrase once. */
+      for(i=0; rc==SQLITE_OK && i<p->nToken && bEof==0; i++){
+        rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+        if( a[i].bIgnore==0 && (bMaxSet==0 || DOCID_CMP(iMax, a[i].iDocid)<0) ){
+          iMax = a[i].iDocid;
+          bMaxSet = 1;
+        }
+      }
+      assert( rc!=SQLITE_OK || a[p->nToken-1].bIgnore==0 );
+      assert( rc!=SQLITE_OK || bMaxSet );
+
+      /* Keep advancing iterators until they all point to the same document */
+      for(i=0; i<p->nToken; i++){
+        while( rc==SQLITE_OK && bEof==0 
+            && a[i].bIgnore==0 && DOCID_CMP(a[i].iDocid, iMax)<0 
+        ){
+          rc = incrPhraseTokenNext(pTab, p, i, &a[i], &bEof);
+          if( DOCID_CMP(a[i].iDocid, iMax)>0 ){
+            iMax = a[i].iDocid;
+            i = 0;
+          }
+        }
+      }
+
+      /* Check if the current entries really are a phrase match */
+      if( bEof==0 ){
+        int nList = 0;
+        int nByte = a[p->nToken-1].nList;
+        char *aDoclist = sqlite3_malloc(nByte+1);
+        if( !aDoclist ) return SQLITE_NOMEM;
+        memcpy(aDoclist, a[p->nToken-1].pList, nByte+1);
+
+        for(i=0; i<(p->nToken-1); i++){
+          if( a[i].bIgnore==0 ){
+            char *pL = a[i].pList;
+            char *pR = aDoclist;
+            char *pOut = aDoclist;
+            int nDist = p->nToken-1-i;
+            int res = fts3PoslistPhraseMerge(&pOut, nDist, 0, 1, &pL, &pR);
+            if( res==0 ) break;
+            nList = (int)(pOut - aDoclist);
+          }
+        }
+        if( i==(p->nToken-1) ){
+          pDL->iDocid = iMax;
+          pDL->pList = aDoclist;
+          pDL->nList = nList;
+          pDL->bFreeList = 1;
+          break;
+        }
+        sqlite3_free(aDoclist);
+      }
     }
+  }
+
+  *pbEof = bEof;
+  return rc;
+}
+
+/*
+** Attempt to move the phrase iterator to point to the next matching docid. 
+** If an error occurs, return an SQLite error code. Otherwise, return 
+** SQLITE_OK.
+**
+** If there is no "next" entry and no error occurs, then *pbEof is set to
+** 1 before returning. Otherwise, if no error occurs and the iterator is
+** successfully advanced, *pbEof is set to 0.
+*/
+static int fts3EvalPhraseNext(
+  Fts3Cursor *pCsr,               /* FTS Cursor handle */
+  Fts3Phrase *p,                  /* Phrase object to advance to next docid */
+  u8 *pbEof                       /* OUT: Set to 1 if EOF */
+){
+  int rc = SQLITE_OK;
+  Fts3Doclist *pDL = &p->doclist;
+  Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
+
+  if( p->bIncr ){
+    rc = fts3EvalIncrPhraseNext(pCsr, p, pbEof);
   }else if( pCsr->bDesc!=pTab->bDescIdx && pDL->nAll ){
     sqlite3Fts3DoclistPrev(pTab->bDescIdx, pDL->aAll, pDL->nAll, 
         &pDL->pNextDocid, &pDL->iDocid, &pDL->nList, pbEof
     );
     pDL->pList = pDL->pNextDocid;
   }else{
-    char *pIter;                            /* Used to iterate through aAll */
-    char *pEnd = &pDL->aAll[pDL->nAll];     /* 1 byte past end of aAll */
-    if( pDL->pNextDocid ){
-      pIter = pDL->pNextDocid;
-    }else{
-      pIter = pDL->aAll;
-    }
-
-    if( pIter>=pEnd ){
-      /* We have already reached the end of this doclist. EOF. */
-      *pbEof = 1;
-    }else{
-      sqlite3_int64 iDelta;
-      pIter += sqlite3Fts3GetVarint(pIter, &iDelta);
-      if( pTab->bDescIdx==0 || pDL->pNextDocid==0 ){
-        pDL->iDocid += iDelta;
-      }else{
-        pDL->iDocid -= iDelta;
-      }
-      pDL->pList = pIter;
-      fts3PoslistCopy(0, &pIter);
-      pDL->nList = (int)(pIter - pDL->pList);
-
-      /* pIter now points just past the 0x00 that terminates the position-
-      ** list for document pDL->iDocid. However, if this position-list was
-      ** edited in place by fts3EvalNearTrim(), then pIter may not actually
-      ** point to the start of the next docid value. The following line deals
-      ** with this case by advancing pIter past the zero-padding added by
-      ** fts3EvalNearTrim().  */
-      while( pIter<pEnd && *pIter==0 ) pIter++;
-
-      pDL->pNextDocid = pIter;
-      assert( pIter>=&pDL->aAll[pDL->nAll] || *pIter );
-      *pbEof = 0;
-    }
+    fts3EvalDlPhraseNext(pTab, pDL, pbEof);
   }
 
   return rc;
@@ -4135,7 +4528,6 @@ static int fts3EvalPhraseNext(
 static void fts3EvalStartReaders(
   Fts3Cursor *pCsr,               /* FTS Cursor handle */
   Fts3Expr *pExpr,                /* Expression to initialize phrases in */
-  int bOptOk,                     /* True to enable incremental loading */
   int *pRc                        /* IN/OUT: Error code */
 ){
   if( pExpr && SQLITE_OK==*pRc ){
@@ -4146,10 +4538,10 @@ static void fts3EvalStartReaders(
         if( pExpr->pPhrase->aToken[i].pDeferred==0 ) break;
       }
       pExpr->bDeferred = (i==nToken);
-      *pRc = fts3EvalPhraseStart(pCsr, bOptOk, pExpr->pPhrase);
+      *pRc = fts3EvalPhraseStart(pCsr, 1, pExpr->pPhrase);
     }else{
-      fts3EvalStartReaders(pCsr, pExpr->pLeft, bOptOk, pRc);
-      fts3EvalStartReaders(pCsr, pExpr->pRight, bOptOk, pRc);
+      fts3EvalStartReaders(pCsr, pExpr->pLeft, pRc);
+      fts3EvalStartReaders(pCsr, pExpr->pRight, pRc);
       pExpr->bDeferred = (pExpr->pLeft->bDeferred && pExpr->pRight->bDeferred);
     }
   }
@@ -4391,7 +4783,7 @@ static int fts3EvalSelectDeferred(
       ** overflowing the 32-bit integer it is stored in. */
       if( ii<12 ) nLoad4 = nLoad4*4;
 
-      if( ii==0 || pTC->pPhrase->nToken>1 ){
+      if( ii==0 || (pTC->pPhrase->nToken>1 && ii!=nToken-1) ){
         /* Either this is the cheapest token in the entire query, or it is
         ** part of a multi-token phrase. Either way, the entire doclist will
         ** (eventually) be loaded into memory. It may as well be now. */
@@ -4471,7 +4863,7 @@ static int fts3EvalStart(Fts3Cursor *pCsr){
   }
 #endif
 
-  fts3EvalStartReaders(pCsr, pCsr->pExpr, 1, &rc);
+  fts3EvalStartReaders(pCsr, pCsr->pExpr, &rc);
   return rc;
 }
 
@@ -4954,6 +5346,16 @@ static int fts3EvalNext(Fts3Cursor *pCsr){
       pCsr->iPrevId = pExpr->iDocid;
     }while( pCsr->isEof==0 && fts3EvalTestDeferredAndNear(pCsr, &rc) );
   }
+
+  /* Check if the cursor is past the end of the docid range specified
+  ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */
+  if( rc==SQLITE_OK && (
+        (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
+     || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)
+  )){
+    pCsr->isEof = 1;
+  }
+
   return rc;
 }
 
@@ -4977,12 +5379,16 @@ static void fts3EvalRestart(
     if( pPhrase ){
       fts3EvalInvalidatePoslist(pPhrase);
       if( pPhrase->bIncr ){
-        assert( pPhrase->nToken==1 );
-        assert( pPhrase->aToken[0].pSegcsr );
-        sqlite3Fts3MsrIncrRestart(pPhrase->aToken[0].pSegcsr);
+        int i;
+        for(i=0; i<pPhrase->nToken; i++){
+          Fts3PhraseToken *pToken = &pPhrase->aToken[i];
+          assert( pToken->pDeferred==0 );
+          if( pToken->pSegcsr ){
+            sqlite3Fts3MsrIncrRestart(pToken->pSegcsr);
+          }
+        }
         *pRc = fts3EvalPhraseStart(pCsr, 0, pPhrase);
       }
-
       pPhrase->doclist.pNextDocid = 0;
       pPhrase->doclist.iDocid = 0;
     }
@@ -5027,7 +5433,7 @@ static void fts3EvalUpdateCounts(Fts3Expr *pExpr){
         pExpr->aMI[iCol*3 + 2] += (iCnt>0);
         if( *p==0x00 ) break;
         p++;
-        p += sqlite3Fts3GetVarint32(p, &iCol);
+        p += fts3GetVarint32(p, &iCol);
       }
     }
 
@@ -5231,15 +5637,23 @@ int sqlite3Fts3EvalPhrasePoslist(
   pIter = pPhrase->doclist.pList;
   if( iDocid!=pCsr->iPrevId || pExpr->bEof ){
     int bDescDoclist = pTab->bDescIdx;      /* For DOCID_CMP macro */
+    int iMul;                     /* +1 if csr dir matches index dir, else -1 */
     int bOr = 0;
     u8 bEof = 0;
-    Fts3Expr *p;
+    u8 bTreeEof = 0;
+    Fts3Expr *p;                  /* Used to iterate from pExpr to root */
+    Fts3Expr *pNear;              /* Most senior NEAR ancestor (or pExpr) */
 
     /* Check if this phrase descends from an OR expression node. If not, 
     ** return NULL. Otherwise, the entry that corresponds to docid 
-    ** pCsr->iPrevId may lie earlier in the doclist buffer. */
+    ** pCsr->iPrevId may lie earlier in the doclist buffer. Or, if the
+    ** tree that the node is part of has been marked as EOF, but the node
+    ** itself is not EOF, then it may point to an earlier entry. */
+    pNear = pExpr;
     for(p=pExpr->pParent; p; p=p->pParent){
       if( p->eType==FTSQUERY_OR ) bOr = 1;
+      if( p->eType==FTSQUERY_NEAR ) pNear = p;
+      if( p->bEof ) bTreeEof = 1;
     }
     if( bOr==0 ) return SQLITE_OK;
 
@@ -5258,29 +5672,59 @@ int sqlite3Fts3EvalPhrasePoslist(
       assert( rc!=SQLITE_OK || pPhrase->bIncr==0 );
       if( rc!=SQLITE_OK ) return rc;
     }
-
-    if( pExpr->bEof ){
-      pIter = 0;
-      iDocid = 0;
+    
+    iMul = ((pCsr->bDesc==bDescDoclist) ? 1 : -1);
+    while( bTreeEof==1 
+        && pNear->bEof==0
+        && (DOCID_CMP(pNear->iDocid, pCsr->iPrevId) * iMul)<0
+    ){
+      int rc = SQLITE_OK;
+      fts3EvalNextRow(pCsr, pExpr, &rc);
+      if( rc!=SQLITE_OK ) return rc;
+      iDocid = pExpr->iDocid;
+      pIter = pPhrase->doclist.pList;
     }
+
     bEof = (pPhrase->doclist.nAll==0);
     assert( bDescDoclist==0 || bDescDoclist==1 );
     assert( pCsr->bDesc==0 || pCsr->bDesc==1 );
 
-    if( pCsr->bDesc==bDescDoclist ){
-      int dummy;
-      while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
-        sqlite3Fts3DoclistPrev(
-            bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
-            &pIter, &iDocid, &dummy, &bEof
-        );
-      }
-    }else{
-      while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
-        sqlite3Fts3DoclistNext(
-            bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
-            &pIter, &iDocid, &bEof
-        );
+    if( bEof==0 ){
+      if( pCsr->bDesc==bDescDoclist ){
+        int dummy;
+        if( pNear->bEof ){
+          /* This expression is already at EOF. So position it to point to the
+          ** last entry in the doclist at pPhrase->doclist.aAll[]. Variable
+          ** iDocid is already set for this entry, so all that is required is
+          ** to set pIter to point to the first byte of the last position-list
+          ** in the doclist. 
+          **
+          ** It would also be correct to set pIter and iDocid to zero. In
+          ** this case, the first call to sqltie3Fts4DoclistPrev() below
+          ** would also move the iterator to point to the last entry in the 
+          ** doclist. However, this is expensive, as to do so it has to 
+          ** iterate through the entire doclist from start to finish (since
+          ** it does not know the docid for the last entry).  */
+          pIter = &pPhrase->doclist.aAll[pPhrase->doclist.nAll-1];
+          fts3ReversePoslist(pPhrase->doclist.aAll, &pIter);
+        }
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)>0 ) && bEof==0 ){
+          sqlite3Fts3DoclistPrev(
+              bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
+              &pIter, &iDocid, &dummy, &bEof
+          );
+        }
+      }else{
+        if( pNear->bEof ){
+          pIter = 0;
+          iDocid = 0;
+        }
+        while( (pIter==0 || DOCID_CMP(iDocid, pCsr->iPrevId)<0 ) && bEof==0 ){
+          sqlite3Fts3DoclistNext(
+              bDescDoclist, pPhrase->doclist.aAll, pPhrase->doclist.nAll, 
+              &pIter, &iDocid, &bEof
+          );
+        }
       }
     }
 
@@ -5290,7 +5734,7 @@ int sqlite3Fts3EvalPhrasePoslist(
 
   if( *pIter==0x01 ){
     pIter++;
-    pIter += sqlite3Fts3GetVarint32(pIter, &iThis);
+    pIter += fts3GetVarint32(pIter, &iThis);
   }else{
     iThis = 0;
   }
@@ -5298,7 +5742,7 @@ int sqlite3Fts3EvalPhrasePoslist(
     fts3ColumnlistCopy(0, &pIter);
     if( *pIter==0x00 ) return 0;
     pIter++;
-    pIter += sqlite3Fts3GetVarint32(pIter, &iThis);
+    pIter += fts3GetVarint32(pIter, &iThis);
   }
 
   *ppOut = ((iCol==iThis)?pIter:0);
@@ -5339,7 +5783,10 @@ int sqlite3Fts3Corrupt(){
 /*
 ** Initialize API pointer table, if required.
 */
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts3_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/ext/fts3/fts3Int.h b/ext/fts3/fts3Int.h
index b19064c..b2827b7 100644
--- a/ext/fts3/fts3Int.h
+++ b/ext/fts3/fts3Int.h
@@ -32,7 +32,7 @@
 /* If not building as part of the core, include sqlite3ext.h. */
 #ifndef SQLITE_CORE
 # include "sqlite3ext.h" 
-extern const sqlite3_api_routines *sqlite3_api;
+SQLITE_EXTENSION_INIT3
 #endif
 
 #include "sqlite3.h"
@@ -40,6 +40,18 @@ extern const sqlite3_api_routines *sqlite3_api;
 #include "fts3_hash.h"
 
 /*
+** This constant determines the maximum depth of an FTS expression tree
+** that the library will create and use. FTS uses recursion to perform 
+** various operations on the query tree, so the disadvantage of a large
+** limit is that it may allow very large queries to use large amounts
+** of stack space (perhaps causing a stack overflow).
+*/
+#ifndef SQLITE_FTS3_MAX_EXPR_DEPTH
+# define SQLITE_FTS3_MAX_EXPR_DEPTH 12
+#endif
+
+
+/*
 ** This constant controls how often segments are merged. Once there are
 ** FTS3_MERGE_COUNT segments of level N, they are merged into a single
 ** segment of level N+1.
@@ -194,23 +206,24 @@ struct Fts3Table {
   const char *zName;              /* virtual table name */
   int nColumn;                    /* number of named columns in virtual table */
   char **azColumn;                /* column names.  malloced */
+  u8 *abNotindexed;               /* True for 'notindexed' columns */
   sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
   char *zContentTbl;              /* content=xxx option, or NULL */
   char *zLanguageid;              /* languageid=xxx option, or NULL */
-  u8 bAutoincrmerge;              /* True if automerge=1 */
+  int nAutoincrmerge;             /* Value configured by 'automerge' */
   u32 nLeafAdd;                   /* Number of leaf blocks added this trans */
 
   /* Precompiled statements used by the implementation. Each of these 
   ** statements is run and reset within a single virtual table API call. 
   */
-  sqlite3_stmt *aStmt[37];
+  sqlite3_stmt *aStmt[40];
 
   char *zReadExprlist;
   char *zWriteExprlist;
 
   int nNodeSize;                  /* Soft limit for node size */
   u8 bFts4;                       /* True for FTS4, false for FTS3 */
-  u8 bHasStat;                    /* True if %_stat table exists */
+  u8 bHasStat;                    /* True if %_stat table exists (2==unknown) */
   u8 bHasDocsize;                 /* True if %_docsize table exists */
   u8 bDescIdx;                    /* True if doclists are in reverse order */
   u8 bIgnoreSavepoint;            /* True to ignore xSavepoint invocations */
@@ -254,6 +267,12 @@ struct Fts3Table {
   int inTransaction;     /* True after xBegin but before xCommit/xRollback */
   int mxSavepoint;       /* Largest valid xSavepoint integer */
 #endif
+
+#ifdef SQLITE_TEST
+  /* True to disable the incremental doclist optimization. This is controled
+  ** by special insert command 'test-no-incr-doclist'.  */
+  int bNoIncrDoclist;
+#endif
 };
 
 /*
@@ -279,7 +298,8 @@ struct Fts3Cursor {
   int eEvalmode;                  /* An FTS3_EVAL_XX constant */
   int nRowAvg;                    /* Average size of database rows, in pages */
   sqlite3_int64 nDoc;             /* Documents in table */
-
+  i64 iMinDocid;                  /* Minimum docid to return */
+  i64 iMaxDocid;                  /* Maximum docid to return */
   int isMatchinfoNeeded;          /* True when aMatchinfo[] needs filling in */
   u32 *aMatchinfo;                /* Information about most recent match */
   int nMatchinfo;                 /* Number of elements in aMatchinfo[] */
@@ -309,6 +329,15 @@ struct Fts3Cursor {
 #define FTS3_DOCID_SEARCH    1    /* Lookup by rowid on %_content table */
 #define FTS3_FULLTEXT_SEARCH 2    /* Full-text index search */
 
+/*
+** The lower 16-bits of the sqlite3_index_info.idxNum value set by
+** the xBestIndex() method contains the Fts3Cursor.eSearch value described
+** above. The upper 16-bits contain a combination of the following
+** bits, used to describe extra constraints on full-text searches.
+*/
+#define FTS3_HAVE_LANGID    0x00010000      /* languageid=? */
+#define FTS3_HAVE_DOCID_GE  0x00020000      /* docid>=? */
+#define FTS3_HAVE_DOCID_LE  0x00040000      /* docid<=? */
 
 struct Fts3Doclist {
   char *aAll;                    /* Array containing doclist (or NULL) */
@@ -421,7 +450,6 @@ int sqlite3Fts3SegReaderPending(
   Fts3Table*,int,const char*,int,int,Fts3SegReader**);
 void sqlite3Fts3SegReaderFree(Fts3SegReader *);
 int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
-int sqlite3Fts3ReadLock(Fts3Table *);
 int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);
 
 int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
@@ -496,6 +524,10 @@ struct Fts3MultiSegReader {
 
 int sqlite3Fts3Incrmerge(Fts3Table*,int,int);
 
+#define fts3GetVarint32(p, piVal) (                                           \
+  (*(u8*)(p)&0x80) ? sqlite3Fts3GetVarint32(p, piVal) : (*piVal=*(u8*)(p), 1) \
+)
+
 /* fts3.c */
 int sqlite3Fts3PutVarint(char *, sqlite3_int64);
 int sqlite3Fts3GetVarint(const char *, sqlite_int64 *);
@@ -553,7 +585,7 @@ int sqlite3Fts3MsrIncrRestart(Fts3MultiSegReader *pCsr);
 int sqlite3Fts3InitTok(sqlite3*, Fts3Hash *);
 
 /* fts3_unicode2.c (functions generated by parsing unicode text files) */
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
 int sqlite3FtsUnicodeFold(int, int);
 int sqlite3FtsUnicodeIsalnum(int);
 int sqlite3FtsUnicodeIsdiacritic(int);
diff --git a/ext/fts3/fts3_aux.c b/ext/fts3/fts3_aux.c
index 9b582fc..c68b1a9 100644
--- a/ext/fts3/fts3_aux.c
+++ b/ext/fts3/fts3_aux.c
@@ -31,6 +31,7 @@ struct Fts3auxCursor {
   Fts3SegFilter filter;
   char *zStop;
   int nStop;                      /* Byte-length of string zStop */
+  int iLangid;                    /* Language id to query */
   int isEof;                      /* True if cursor is at EOF */
   sqlite3_int64 iRowid;           /* Current rowid */
 
@@ -45,7 +46,8 @@ struct Fts3auxCursor {
 /*
 ** Schema of the terms table.
 */
-#define FTS3_TERMS_SCHEMA "CREATE TABLE x(term, col, documents, occurrences)"
+#define FTS3_AUX_SCHEMA \
+  "CREATE TABLE x(term, col, documents, occurrences, languageid HIDDEN)"
 
 /*
 ** This function does all the work for both the xConnect and xCreate methods.
@@ -92,7 +94,7 @@ static int fts3auxConnectMethod(
   }
   nFts3 = (int)strlen(zFts3);
 
-  rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA);
+  rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA);
   if( rc!=SQLITE_OK ) return rc;
 
   nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2;
@@ -152,6 +154,8 @@ static int fts3auxBestIndexMethod(
   int iEq = -1;
   int iGe = -1;
   int iLe = -1;
+  int iLangid = -1;
+  int iNext = 1;                  /* Next free argvIndex value */
 
   UNUSED_PARAMETER(pVTab);
 
@@ -163,36 +167,48 @@ static int fts3auxBestIndexMethod(
     pInfo->orderByConsumed = 1;
   }
 
-  /* Search for equality and range constraints on the "term" column. */
+  /* Search for equality and range constraints on the "term" column. 
+  ** And equality constraints on the hidden "languageid" column. */
   for(i=0; i<pInfo->nConstraint; i++){
-    if( pInfo->aConstraint[i].usable && pInfo->aConstraint[i].iColumn==0 ){
+    if( pInfo->aConstraint[i].usable ){
       int op = pInfo->aConstraint[i].op;
-      if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
-      if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
+      int iCol = pInfo->aConstraint[i].iColumn;
+
+      if( iCol==0 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i;
+        if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i;
+      }
+      if( iCol==4 ){
+        if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iLangid = i;
+      }
     }
   }
 
   if( iEq>=0 ){
     pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT;
-    pInfo->aConstraintUsage[iEq].argvIndex = 1;
+    pInfo->aConstraintUsage[iEq].argvIndex = iNext++;
     pInfo->estimatedCost = 5;
   }else{
     pInfo->idxNum = 0;
     pInfo->estimatedCost = 20000;
     if( iGe>=0 ){
       pInfo->idxNum += FTS4AUX_GE_CONSTRAINT;
-      pInfo->aConstraintUsage[iGe].argvIndex = 1;
+      pInfo->aConstraintUsage[iGe].argvIndex = iNext++;
       pInfo->estimatedCost /= 2;
     }
     if( iLe>=0 ){
       pInfo->idxNum += FTS4AUX_LE_CONSTRAINT;
-      pInfo->aConstraintUsage[iLe].argvIndex = 1 + (iGe>=0);
+      pInfo->aConstraintUsage[iLe].argvIndex = iNext++;
       pInfo->estimatedCost /= 2;
     }
   }
+  if( iLangid>=0 ){
+    pInfo->aConstraintUsage[iLangid].argvIndex = iNext++;
+    pInfo->estimatedCost--;
+  }
 
   return SQLITE_OK;
 }
@@ -352,7 +368,14 @@ static int fts3auxFilterMethod(
   Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor;
   Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab;
   int rc;
-  int isScan;
+  int isScan = 0;
+  int iLangVal = 0;               /* Language id to query */
+
+  int iEq = -1;                   /* Index of term=? value in apVal */
+  int iGe = -1;                   /* Index of term>=? value in apVal */
+  int iLe = -1;                   /* Index of term<=? value in apVal */
+  int iLangid = -1;               /* Index of languageid=? value in apVal */
+  int iNext = 0;
 
   UNUSED_PARAMETER(nVal);
   UNUSED_PARAMETER(idxStr);
@@ -362,7 +385,21 @@ static int fts3auxFilterMethod(
        || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT
        || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT)
   );
-  isScan = (idxNum!=FTS4AUX_EQ_CONSTRAINT);
+
+  if( idxNum==FTS4AUX_EQ_CONSTRAINT ){
+    iEq = iNext++;
+  }else{
+    isScan = 1;
+    if( idxNum & FTS4AUX_GE_CONSTRAINT ){
+      iGe = iNext++;
+    }
+    if( idxNum & FTS4AUX_LE_CONSTRAINT ){
+      iLe = iNext++;
+    }
+  }
+  if( iNext<nVal ){
+    iLangid = iNext++;
+  }
 
   /* In case this cursor is being reused, close and zero it. */
   testcase(pCsr->filter.zTerm);
@@ -374,22 +411,35 @@ static int fts3auxFilterMethod(
   pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY;
   if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN;
 
-  if( idxNum&(FTS4AUX_EQ_CONSTRAINT|FTS4AUX_GE_CONSTRAINT) ){
+  if( iEq>=0 || iGe>=0 ){
     const unsigned char *zStr = sqlite3_value_text(apVal[0]);
+    assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) );
     if( zStr ){
       pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr);
       pCsr->filter.nTerm = sqlite3_value_bytes(apVal[0]);
       if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM;
     }
   }
-  if( idxNum&FTS4AUX_LE_CONSTRAINT ){
-    int iIdx = (idxNum&FTS4AUX_GE_CONSTRAINT) ? 1 : 0;
-    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iIdx]));
-    pCsr->nStop = sqlite3_value_bytes(apVal[iIdx]);
+
+  if( iLe>=0 ){
+    pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe]));
+    pCsr->nStop = sqlite3_value_bytes(apVal[iLe]);
     if( pCsr->zStop==0 ) return SQLITE_NOMEM;
   }
+  
+  if( iLangid>=0 ){
+    iLangVal = sqlite3_value_int(apVal[iLangid]);
+
+    /* If the user specified a negative value for the languageid, use zero
+    ** instead. This works, as the "languageid=?" constraint will also
+    ** be tested by the VDBE layer. The test will always be false (since
+    ** this module will not return a row with a negative languageid), and
+    ** so the overall query will return zero rows.  */
+    if( iLangVal<0 ) iLangVal = 0;
+  }
+  pCsr->iLangid = iLangVal;
 
-  rc = sqlite3Fts3SegReaderCursor(pFts3, 0, 0, FTS3_SEGCURSOR_ALL,
+  rc = sqlite3Fts3SegReaderCursor(pFts3, iLangVal, 0, FTS3_SEGCURSOR_ALL,
       pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr
   );
   if( rc==SQLITE_OK ){
@@ -413,24 +463,37 @@ static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){
 */
 static int fts3auxColumnMethod(
   sqlite3_vtab_cursor *pCursor,   /* Cursor to retrieve value from */
-  sqlite3_context *pContext,      /* Context for sqlite3_result_xxx() calls */
+  sqlite3_context *pCtx,          /* Context for sqlite3_result_xxx() calls */
   int iCol                        /* Index of column to read value from */
 ){
   Fts3auxCursor *p = (Fts3auxCursor *)pCursor;
 
   assert( p->isEof==0 );
-  if( iCol==0 ){        /* Column "term" */
-    sqlite3_result_text(pContext, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
-  }else if( iCol==1 ){  /* Column "col" */
-    if( p->iCol ){
-      sqlite3_result_int(pContext, p->iCol-1);
-    }else{
-      sqlite3_result_text(pContext, "*", -1, SQLITE_STATIC);
-    }
-  }else if( iCol==2 ){  /* Column "documents" */
-    sqlite3_result_int64(pContext, p->aStat[p->iCol].nDoc);
-  }else{                /* Column "occurrences" */
-    sqlite3_result_int64(pContext, p->aStat[p->iCol].nOcc);
+  switch( iCol ){
+    case 0: /* term */
+      sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT);
+      break;
+
+    case 1: /* col */
+      if( p->iCol ){
+        sqlite3_result_int(pCtx, p->iCol-1);
+      }else{
+        sqlite3_result_text(pCtx, "*", -1, SQLITE_STATIC);
+      }
+      break;
+
+    case 2: /* documents */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nDoc);
+      break;
+
+    case 3: /* occurrences */
+      sqlite3_result_int64(pCtx, p->aStat[p->iCol].nOcc);
+      break;
+
+    default: /* languageid */
+      assert( iCol==4 );
+      sqlite3_result_int(pCtx, p->iLangid);
+      break;
   }
 
   return SQLITE_OK;
diff --git a/ext/fts3/fts3_expr.c b/ext/fts3/fts3_expr.c
index c046d7d..f5d28cb 100644
--- a/ext/fts3/fts3_expr.c
+++ b/ext/fts3/fts3_expr.c
@@ -155,6 +155,11 @@ int sqlite3Fts3OpenTokenizer(
   return rc;
 }
 
+/*
+** Function getNextNode(), which is called by fts3ExprParse(), may itself
+** call fts3ExprParse(). So this forward declaration is required.
+*/
+static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);
 
 /*
 ** Extract the next token from buffer z (length n) using the tokenizer
@@ -180,9 +185,16 @@ static int getNextToken(
   int rc;
   sqlite3_tokenizer_cursor *pCursor;
   Fts3Expr *pRet = 0;
-  int nConsumed = 0;
+  int i = 0;
+
+  /* Set variable i to the maximum number of bytes of input to tokenize. */
+  for(i=0; i<n; i++){
+    if( sqlite3_fts3_enable_parentheses && (z[i]=='(' || z[i]==')') ) break;
+    if( z[i]=='*' || z[i]=='"' ) break;
+  }
 
-  rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, n, &pCursor);
+  *pnConsumed = i;
+  rc = sqlite3Fts3OpenTokenizer(pTokenizer, pParse->iLangid, z, i, &pCursor);
   if( rc==SQLITE_OK ){
     const char *zToken;
     int nToken = 0, iStart = 0, iEnd = 0, iPosition = 0;
@@ -223,13 +235,14 @@ static int getNextToken(
         }
 
       }
-      nConsumed = iEnd;
+      *pnConsumed = iEnd;
+    }else if( i && rc==SQLITE_DONE ){
+      rc = SQLITE_OK;
     }
 
     pModule->xClose(pCursor);
   }
   
-  *pnConsumed = nConsumed;
   *ppExpr = pRet;
   return rc;
 }
@@ -370,12 +383,6 @@ no_mem:
 }
 
 /*
-** Function getNextNode(), which is called by fts3ExprParse(), may itself
-** call fts3ExprParse(). So this forward declaration is required.
-*/
-static int fts3ExprParse(ParseContext *, const char *, int, Fts3Expr **, int *);
-
-/*
 ** The output variable *ppExpr is populated with an allocated Fts3Expr 
 ** structure, or set to 0 if the end of the input buffer is reached.
 **
@@ -471,27 +478,6 @@ static int getNextNode(
     }
   }
 
-  /* Check for an open bracket. */
-  if( sqlite3_fts3_enable_parentheses ){
-    if( *zInput=='(' ){
-      int nConsumed;
-      pParse->nNest++;
-      rc = fts3ExprParse(pParse, &zInput[1], nInput-1, ppExpr, &nConsumed);
-      if( rc==SQLITE_OK && !*ppExpr ){
-        rc = SQLITE_DONE;
-      }
-      *pnConsumed = (int)((zInput - z) + 1 + nConsumed);
-      return rc;
-    }
-  
-    /* Check for a close bracket. */
-    if( *zInput==')' ){
-      pParse->nNest--;
-      *pnConsumed = (int)((zInput - z) + 1);
-      return SQLITE_DONE;
-    }
-  }
-
   /* See if we are dealing with a quoted phrase. If this is the case, then
   ** search for the closing quote and pass the whole string to getNextString()
   ** for processing. This is easy to do, as fts3 has no syntax for escaping
@@ -506,6 +492,21 @@ static int getNextNode(
     return getNextString(pParse, &zInput[1], ii-1, ppExpr);
   }
 
+  if( sqlite3_fts3_enable_parentheses ){
+    if( *zInput=='(' ){
+      int nConsumed = 0;
+      pParse->nNest++;
+      rc = fts3ExprParse(pParse, zInput+1, nInput-1, ppExpr, &nConsumed);
+      if( rc==SQLITE_OK && !*ppExpr ){ rc = SQLITE_DONE; }
+      *pnConsumed = (int)(zInput - z) + 1 + nConsumed;
+      return rc;
+    }else if( *zInput==')' ){
+      pParse->nNest--;
+      *pnConsumed = (int)((zInput - z) + 1);
+      *ppExpr = 0;
+      return SQLITE_DONE;
+    }
+  }
 
   /* If control flows to this point, this must be a regular token, or 
   ** the end of the input. Read a regular token using the sqlite3_tokenizer
@@ -624,96 +625,100 @@ static int fts3ExprParse(
   while( rc==SQLITE_OK ){
     Fts3Expr *p = 0;
     int nByte = 0;
+
     rc = getNextNode(pParse, zIn, nIn, &p, &nByte);
+    assert( nByte>0 || (rc!=SQLITE_OK && p==0) );
     if( rc==SQLITE_OK ){
-      int isPhrase;
-
-      if( !sqlite3_fts3_enable_parentheses 
-       && p->eType==FTSQUERY_PHRASE && pParse->isNot 
-      ){
-        /* Create an implicit NOT operator. */
-        Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
-        if( !pNot ){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_NOMEM;
-          goto exprparse_out;
-        }
-        pNot->eType = FTSQUERY_NOT;
-        pNot->pRight = p;
-        p->pParent = pNot;
-        if( pNotBranch ){
-          pNot->pLeft = pNotBranch;
-          pNotBranch->pParent = pNot;
-        }
-        pNotBranch = pNot;
-        p = pPrev;
-      }else{
-        int eType = p->eType;
-        isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);
-
-        /* The isRequirePhrase variable is set to true if a phrase or
-        ** an expression contained in parenthesis is required. If a
-        ** binary operator (AND, OR, NOT or NEAR) is encounted when
-        ** isRequirePhrase is set, this is a syntax error.
-        */
-        if( !isPhrase && isRequirePhrase ){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_ERROR;
-          goto exprparse_out;
-        }
-  
-        if( isPhrase && !isRequirePhrase ){
-          /* Insert an implicit AND operator. */
-          Fts3Expr *pAnd;
-          assert( pRet && pPrev );
-          pAnd = fts3MallocZero(sizeof(Fts3Expr));
-          if( !pAnd ){
+      if( p ){
+        int isPhrase;
+
+        if( !sqlite3_fts3_enable_parentheses 
+            && p->eType==FTSQUERY_PHRASE && pParse->isNot 
+        ){
+          /* Create an implicit NOT operator. */
+          Fts3Expr *pNot = fts3MallocZero(sizeof(Fts3Expr));
+          if( !pNot ){
             sqlite3Fts3ExprFree(p);
             rc = SQLITE_NOMEM;
             goto exprparse_out;
           }
-          pAnd->eType = FTSQUERY_AND;
-          insertBinaryOperator(&pRet, pPrev, pAnd);
-          pPrev = pAnd;
-        }
+          pNot->eType = FTSQUERY_NOT;
+          pNot->pRight = p;
+          p->pParent = pNot;
+          if( pNotBranch ){
+            pNot->pLeft = pNotBranch;
+            pNotBranch->pParent = pNot;
+          }
+          pNotBranch = pNot;
+          p = pPrev;
+        }else{
+          int eType = p->eType;
+          isPhrase = (eType==FTSQUERY_PHRASE || p->pLeft);
+
+          /* The isRequirePhrase variable is set to true if a phrase or
+          ** an expression contained in parenthesis is required. If a
+          ** binary operator (AND, OR, NOT or NEAR) is encounted when
+          ** isRequirePhrase is set, this is a syntax error.
+          */
+          if( !isPhrase && isRequirePhrase ){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase && !isRequirePhrase ){
+            /* Insert an implicit AND operator. */
+            Fts3Expr *pAnd;
+            assert( pRet && pPrev );
+            pAnd = fts3MallocZero(sizeof(Fts3Expr));
+            if( !pAnd ){
+              sqlite3Fts3ExprFree(p);
+              rc = SQLITE_NOMEM;
+              goto exprparse_out;
+            }
+            pAnd->eType = FTSQUERY_AND;
+            insertBinaryOperator(&pRet, pPrev, pAnd);
+            pPrev = pAnd;
+          }
 
-        /* This test catches attempts to make either operand of a NEAR
-        ** operator something other than a phrase. For example, either of
-        ** the following:
-        **
-        **    (bracketed expression) NEAR phrase
-        **    phrase NEAR (bracketed expression)
-        **
-        ** Return an error in either case.
-        */
-        if( pPrev && (
+          /* This test catches attempts to make either operand of a NEAR
+           ** operator something other than a phrase. For example, either of
+           ** the following:
+           **
+           **    (bracketed expression) NEAR phrase
+           **    phrase NEAR (bracketed expression)
+           **
+           ** Return an error in either case.
+           */
+          if( pPrev && (
             (eType==FTSQUERY_NEAR && !isPhrase && pPrev->eType!=FTSQUERY_PHRASE)
          || (eType!=FTSQUERY_PHRASE && isPhrase && pPrev->eType==FTSQUERY_NEAR)
-        )){
-          sqlite3Fts3ExprFree(p);
-          rc = SQLITE_ERROR;
-          goto exprparse_out;
-        }
-  
-        if( isPhrase ){
-          if( pRet ){
-            assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );
-            pPrev->pRight = p;
-            p->pParent = pPrev;
+          )){
+            sqlite3Fts3ExprFree(p);
+            rc = SQLITE_ERROR;
+            goto exprparse_out;
+          }
+
+          if( isPhrase ){
+            if( pRet ){
+              assert( pPrev && pPrev->pLeft && pPrev->pRight==0 );
+              pPrev->pRight = p;
+              p->pParent = pPrev;
+            }else{
+              pRet = p;
+            }
           }else{
-            pRet = p;
+            insertBinaryOperator(&pRet, pPrev, p);
           }
-        }else{
-          insertBinaryOperator(&pRet, pPrev, p);
+          isRequirePhrase = !isPhrase;
         }
-        isRequirePhrase = !isPhrase;
+        pPrev = p;
       }
       assert( nByte>0 );
     }
     assert( rc!=SQLITE_OK || (nByte>0 && nByte<=nIn) );
     nIn -= nByte;
     zIn += nByte;
-    pPrev = p;
   }
 
   if( rc==SQLITE_DONE && pRet && isRequirePhrase ){
@@ -1000,17 +1005,16 @@ int sqlite3Fts3ExprParse(
   Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
   char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
 ){
-  static const int MAX_EXPR_DEPTH = 12;
   int rc = fts3ExprParseUnbalanced(
       pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
   );
   
   /* Rebalance the expression. And check that its depth does not exceed
-  ** MAX_EXPR_DEPTH.  */
+  ** SQLITE_FTS3_MAX_EXPR_DEPTH.  */
   if( rc==SQLITE_OK && *ppExpr ){
-    rc = fts3ExprBalance(ppExpr, MAX_EXPR_DEPTH);
+    rc = fts3ExprBalance(ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
     if( rc==SQLITE_OK ){
-      rc = fts3ExprCheckDepth(*ppExpr, MAX_EXPR_DEPTH);
+      rc = fts3ExprCheckDepth(*ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
     }
   }
 
@@ -1019,7 +1023,8 @@ int sqlite3Fts3ExprParse(
     *ppExpr = 0;
     if( rc==SQLITE_TOOBIG ){
       *pzErr = sqlite3_mprintf(
-          "FTS expression tree is too large (maximum depth %d)", MAX_EXPR_DEPTH
+          "FTS expression tree is too large (maximum depth %d)", 
+          SQLITE_FTS3_MAX_EXPR_DEPTH
       );
       rc = SQLITE_ERROR;
     }else if( rc==SQLITE_ERROR ){
diff --git a/ext/fts3/fts3_hash.c b/ext/fts3/fts3_hash.c
index 57c59b5..1a32a53 100644
--- a/ext/fts3/fts3_hash.c
+++ b/ext/fts3/fts3_hash.c
@@ -96,13 +96,13 @@ void sqlite3Fts3HashClear(Fts3Hash *pH){
 */
 static int fts3StrHash(const void *pKey, int nKey){
   const char *z = (const char *)pKey;
-  int h = 0;
+  unsigned h = 0;
   if( nKey<=0 ) nKey = (int) strlen(z);
   while( nKey > 0  ){
     h = (h<<3) ^ h ^ *z++;
     nKey--;
   }
-  return h & 0x7fffffff;
+  return (int)(h & 0x7fffffff);
 }
 static int fts3StrCompare(const void *pKey1, int n1, const void *pKey2, int n2){
   if( n1!=n2 ) return 1;
diff --git a/ext/fts3/fts3_porter.c b/ext/fts3/fts3_porter.c
index 579745b..db175ac 100644
--- a/ext/fts3/fts3_porter.c
+++ b/ext/fts3/fts3_porter.c
@@ -403,12 +403,14 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
   /* Step 2 */
   switch( z[1] ){
    case 'a':
-     stem(&z, "lanoita", "ate", m_gt_0) ||
-     stem(&z, "lanoit", "tion", m_gt_0);
+     if( !stem(&z, "lanoita", "ate", m_gt_0) ){
+       stem(&z, "lanoit", "tion", m_gt_0);
+     }
      break;
    case 'c':
-     stem(&z, "icne", "ence", m_gt_0) ||
-     stem(&z, "icna", "ance", m_gt_0);
+     if( !stem(&z, "icne", "ence", m_gt_0) ){
+       stem(&z, "icna", "ance", m_gt_0);
+     }
      break;
    case 'e':
      stem(&z, "rezi", "ize", m_gt_0);
@@ -417,43 +419,54 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
      stem(&z, "igol", "log", m_gt_0);
      break;
    case 'l':
-     stem(&z, "ilb", "ble", m_gt_0) ||
-     stem(&z, "illa", "al", m_gt_0) ||
-     stem(&z, "iltne", "ent", m_gt_0) ||
-     stem(&z, "ile", "e", m_gt_0) ||
-     stem(&z, "ilsuo", "ous", m_gt_0);
+     if( !stem(&z, "ilb", "ble", m_gt_0) 
+      && !stem(&z, "illa", "al", m_gt_0)
+      && !stem(&z, "iltne", "ent", m_gt_0)
+      && !stem(&z, "ile", "e", m_gt_0)
+     ){
+       stem(&z, "ilsuo", "ous", m_gt_0);
+     }
      break;
    case 'o':
-     stem(&z, "noitazi", "ize", m_gt_0) ||
-     stem(&z, "noita", "ate", m_gt_0) ||
-     stem(&z, "rota", "ate", m_gt_0);
+     if( !stem(&z, "noitazi", "ize", m_gt_0)
+      && !stem(&z, "noita", "ate", m_gt_0)
+     ){
+       stem(&z, "rota", "ate", m_gt_0);
+     }
      break;
    case 's':
-     stem(&z, "msila", "al", m_gt_0) ||
-     stem(&z, "ssenevi", "ive", m_gt_0) ||
-     stem(&z, "ssenluf", "ful", m_gt_0) ||
-     stem(&z, "ssensuo", "ous", m_gt_0);
+     if( !stem(&z, "msila", "al", m_gt_0)
+      && !stem(&z, "ssenevi", "ive", m_gt_0)
+      && !stem(&z, "ssenluf", "ful", m_gt_0)
+     ){
+       stem(&z, "ssensuo", "ous", m_gt_0);
+     }
      break;
    case 't':
-     stem(&z, "itila", "al", m_gt_0) ||
-     stem(&z, "itivi", "ive", m_gt_0) ||
-     stem(&z, "itilib", "ble", m_gt_0);
+     if( !stem(&z, "itila", "al", m_gt_0)
+      && !stem(&z, "itivi", "ive", m_gt_0)
+     ){
+       stem(&z, "itilib", "ble", m_gt_0);
+     }
      break;
   }
 
   /* Step 3 */
   switch( z[0] ){
    case 'e':
-     stem(&z, "etaci", "ic", m_gt_0) ||
-     stem(&z, "evita", "", m_gt_0)   ||
-     stem(&z, "ezila", "al", m_gt_0);
+     if( !stem(&z, "etaci", "ic", m_gt_0)
+      && !stem(&z, "evita", "", m_gt_0)
+     ){
+       stem(&z, "ezila", "al", m_gt_0);
+     }
      break;
    case 'i':
      stem(&z, "itici", "ic", m_gt_0);
      break;
    case 'l':
-     stem(&z, "laci", "ic", m_gt_0) ||
-     stem(&z, "luf", "", m_gt_0);
+     if( !stem(&z, "laci", "ic", m_gt_0) ){
+       stem(&z, "luf", "", m_gt_0);
+     }
      break;
    case 's':
      stem(&z, "ssen", "", m_gt_0);
@@ -494,9 +507,11 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
            z += 3;
          }
        }else if( z[2]=='e' ){
-         stem(&z, "tneme", "", m_gt_1) ||
-         stem(&z, "tnem", "", m_gt_1) ||
-         stem(&z, "tne", "", m_gt_1);
+         if( !stem(&z, "tneme", "", m_gt_1)
+          && !stem(&z, "tnem", "", m_gt_1)
+         ){
+           stem(&z, "tne", "", m_gt_1);
+         }
        }
      }
      break;
@@ -515,8 +530,9 @@ static void porter_stemmer(const char *zIn, int nIn, char *zOut, int *pnOut){
      }
      break;
    case 't':
-     stem(&z, "eta", "", m_gt_1) ||
-     stem(&z, "iti", "", m_gt_1);
+     if( !stem(&z, "eta", "", m_gt_1) ){
+       stem(&z, "iti", "", m_gt_1);
+     }
      break;
    case 'u':
      if( z[0]=='s' && z[2]=='o' && m_gt_1(z+3) ){
diff --git a/ext/fts3/fts3_snippet.c b/ext/fts3/fts3_snippet.c
index d54a787..aa8779f 100644
--- a/ext/fts3/fts3_snippet.c
+++ b/ext/fts3/fts3_snippet.c
@@ -128,7 +128,7 @@ struct StrBuffer {
 */
 static void fts3GetDeltaPosition(char **pp, int *piPos){
   int iVal;
-  *pp += sqlite3Fts3GetVarint32(*pp, &iVal);
+  *pp += fts3GetVarint32(*pp, &iVal);
   *piPos += (iVal-2);
 }
 
@@ -504,6 +504,7 @@ static int fts3StringAppend(
     pStr->z = zNew;
     pStr->nAlloc = nAlloc;
   }
+  assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );
 
   /* Append the data to the string buffer. */
   memcpy(&pStr->z[pStr->n], zAppend, nAppend);
diff --git a/ext/fts3/fts3_test.c b/ext/fts3/fts3_test.c
index 75ec6bd..36dcc94 100644
--- a/ext/fts3/fts3_test.c
+++ b/ext/fts3/fts3_test.c
@@ -517,6 +517,51 @@ static int fts3_test_tokenizer_cmd(
   return TCL_OK;
 }
 
+static int fts3_test_varint_cmd(
+  ClientData clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+#ifdef SQLITE_ENABLE_FTS3
+  char aBuf[24];
+  int rc;
+  Tcl_WideInt w, w2;
+  int nByte, nByte2;
+
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "INTEGER");
+    return TCL_ERROR;
+  }
+
+  rc = Tcl_GetWideIntFromObj(interp, objv[1], &w);
+  if( rc!=TCL_OK ) return rc;
+
+  nByte = sqlite3Fts3PutVarint(aBuf, w);
+  nByte2 = sqlite3Fts3GetVarint(aBuf, &w2);
+  if( w!=w2 || nByte!=nByte2 ){
+    char *zErr = sqlite3_mprintf("error testing %lld", w);
+    Tcl_ResetResult(interp);
+    Tcl_AppendResult(interp, zErr, 0);
+    return TCL_ERROR;
+  }
+
+  if( w<=2147483647 && w>=0 ){
+    int i;
+    nByte2 = fts3GetVarint32(aBuf, &i);
+    if( (int)w!=i || nByte!=nByte2 ){
+      char *zErr = sqlite3_mprintf("error testing %lld (32-bit)", w);
+      Tcl_ResetResult(interp);
+      Tcl_AppendResult(interp, zErr, 0);
+      return TCL_ERROR;
+    }
+  }
+
+#endif
+  UNUSED_PARAMETER(clientData);
+  return TCL_OK;
+}
+
 /* 
 ** End of tokenizer code.
 **************************************************************************/ 
@@ -529,6 +574,10 @@ int Sqlitetestfts3_Init(Tcl_Interp *interp){
   Tcl_CreateObjCommand(
       interp, "fts3_test_tokenizer", fts3_test_tokenizer_cmd, 0, 0
   );
+
+  Tcl_CreateObjCommand(
+      interp, "fts3_test_varint", fts3_test_varint_cmd, 0, 0
+  );
   return TCL_OK;
 }
 #endif                  /* SQLITE_ENABLE_FTS3 || SQLITE_ENABLE_FTS4 */
diff --git a/ext/fts3/fts3_unicode.c b/ext/fts3/fts3_unicode.c
index 188358e..94fc27b 100644
--- a/ext/fts3/fts3_unicode.c
+++ b/ext/fts3/fts3_unicode.c
@@ -13,7 +13,7 @@
 ** Implementation of the "unicode" full-text-search tokenizer.
 */
 
-#ifdef SQLITE_ENABLE_FTS4_UNICODE61
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
 
 #include "fts3Int.h"
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3)
@@ -231,7 +231,7 @@ static int unicodeCreate(
 
   for(i=0; rc==SQLITE_OK && i<nArg; i++){
     const char *z = azArg[i];
-    int n = strlen(z);
+    int n = (int)strlen(z);
 
     if( n==19 && memcmp("remove_diacritics=1", z, 19)==0 ){
       pNew->bRemoveDiacritic = 1;
@@ -318,7 +318,7 @@ static int unicodeNext(
 ){
   unicode_cursor *pCsr = (unicode_cursor *)pC;
   unicode_tokenizer *p = ((unicode_tokenizer *)pCsr->base.pTokenizer);
-  int iCode;
+  int iCode = 0;
   char *zOut;
   const unsigned char *z = &pCsr->aInput[pCsr->iOff];
   const unsigned char *zStart = z;
@@ -363,11 +363,11 @@ static int unicodeNext(
   );
 
   /* Set the output variables and return. */
-  pCsr->iOff = (z - pCsr->aInput);
+  pCsr->iOff = (int)(z - pCsr->aInput);
   *paToken = pCsr->zToken;
-  *pnToken = zOut - pCsr->zToken;
-  *piStart = (zStart - pCsr->aInput);
-  *piEnd = (zEnd - pCsr->aInput);
+  *pnToken = (int)(zOut - pCsr->zToken);
+  *piStart = (int)(zStart - pCsr->aInput);
+  *piEnd = (int)(zEnd - pCsr->aInput);
   *piPos = pCsr->iToken++;
   return SQLITE_OK;
 }
@@ -390,4 +390,4 @@ void sqlite3Fts3UnicodeTokenizer(sqlite3_tokenizer_module const **ppModule){
 }
 
 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */
-#endif /* ifndef SQLITE_ENABLE_FTS4_UNICODE61 */
+#endif /* ifndef SQLITE_DISABLE_FTS3_UNICODE */
diff --git a/ext/fts3/fts3_unicode2.c b/ext/fts3/fts3_unicode2.c
index 3c24569..20b7a25 100644
--- a/ext/fts3/fts3_unicode2.c
+++ b/ext/fts3/fts3_unicode2.c
@@ -15,7 +15,7 @@
 ** DO NOT EDIT THIS MACHINE GENERATED FILE.
 */
 
-#if defined(SQLITE_ENABLE_FTS4_UNICODE61)
+#ifndef SQLITE_DISABLE_FTS3_UNICODE
 #if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
 
 #include <assert.h>
@@ -39,7 +39,7 @@ int sqlite3FtsUnicodeIsalnum(int c){
   ** C. It is not possible to represent a range larger than 1023 codepoints 
   ** using this format.
   */
-  const static unsigned int aEntry[] = {
+  static const unsigned int aEntry[] = {
     0x00000030, 0x0000E807, 0x00016C06, 0x0001EC2F, 0x0002AC07,
     0x0002D001, 0x0002D803, 0x0002EC01, 0x0002FC01, 0x00035C01,
     0x0003DC01, 0x000B0804, 0x000B480E, 0x000B9407, 0x000BB401,
@@ -101,28 +101,27 @@ int sqlite3FtsUnicodeIsalnum(int c){
     0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,
     0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,
     0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,
-    0x037FFC02, 0x03E3FC01, 0x03EC7801, 0x03ECA401, 0x03EEC810,
-    0x03F4F802, 0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023,
-    0x03F95013, 0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807,
-    0x03FCEC06, 0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405,
-    0x04040003, 0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E,
-    0x040E7C01, 0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01,
-    0x04280403, 0x04281402, 0x04283004, 0x0428E003, 0x0428FC01,
-    0x04294009, 0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016,
-    0x04420003, 0x0442C012, 0x04440003, 0x04449C0E, 0x04450004,
-    0x04460003, 0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004,
-    0x05BD442E, 0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5,
-    0x07480046, 0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01,
-    0x075C5401, 0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401,
-    0x075EA401, 0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064,
-    0x07C2800F, 0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F,
-    0x07C4C03C, 0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009,
-    0x07C94002, 0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014,
-    0x07CE8025, 0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001,
-    0x07D108B6, 0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018,
-    0x07D7EC46, 0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401,
-    0x38008060, 0x380400F0, 0x3C000001, 0x3FFFF401, 0x40000001,
-    0x43FFF401,
+    0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,
+    0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,
+    0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,
+    0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,
+    0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,
+    0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,
+    0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,
+    0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,
+    0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,
+    0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,
+    0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,
+    0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,
+    0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,
+    0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,
+    0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,
+    0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,
+    0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,
+    0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,
+    0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,
+    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
+    0x380400F0,
   };
   static const unsigned int aAscii[4] = {
     0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
@@ -132,7 +131,7 @@ int sqlite3FtsUnicodeIsalnum(int c){
     return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
   }else if( c<(1<<22) ){
     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
-    int iRes;
+    int iRes = 0;
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     while( iHi>=iLo ){
@@ -203,7 +202,7 @@ static int remove_diacritic(int c){
   }
   assert( key>=aDia[iRes] );
   return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);
-};
+}
 
 
 /*
@@ -363,4 +362,4 @@ int sqlite3FtsUnicodeFold(int c, int bRemoveDiacritic){
   return ret;
 }
 #endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */
-#endif /* !defined(SQLITE_ENABLE_FTS4_UNICODE61) */
+#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */
diff --git a/ext/fts3/fts3_write.c b/ext/fts3/fts3_write.c
index 269d1dd..0da08c6 100644
--- a/ext/fts3/fts3_write.c
+++ b/ext/fts3/fts3_write.c
@@ -193,6 +193,7 @@ struct SegmentWriter {
   int nSize;                      /* Size of allocation at aData */
   int nData;                      /* Bytes of data in aData */
   char *aData;                    /* Pointer to block from malloc() */
+  i64 nLeafData;                  /* Number of bytes of leaf data written */
 };
 
 /*
@@ -268,6 +269,10 @@ struct SegmentNode {
 #define SQL_SELECT_INDEXES            35
 #define SQL_SELECT_MXLEVEL            36
 
+#define SQL_SELECT_LEVEL_RANGE2       37
+#define SQL_UPDATE_LEVEL_IDX          38
+#define SQL_UPDATE_LEVEL              39
+
 /*
 ** This function is used to obtain an SQLite prepared statement handle
 ** for the statement identified by the second argument. If successful,
@@ -369,7 +374,18 @@ static int fts3SqlStmt(
 
 /* SQL_SELECT_MXLEVEL
 **   Return the largest relative level in the FTS index or indexes.  */
-/* 36 */  "SELECT max( level %% 1024 ) FROM %Q.'%q_segdir'"
+/* 36 */  "SELECT max( level %% 1024 ) FROM %Q.'%q_segdir'",
+
+          /* Return segments in order from oldest to newest.*/ 
+/* 37 */  "SELECT level, idx, end_block "
+            "FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ? "
+            "ORDER BY level DESC, idx ASC",
+
+          /* Update statements used while promoting segments */
+/* 38 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=-1,idx=? "
+            "WHERE level=? AND idx=?",
+/* 39 */  "UPDATE OR FAIL %Q.'%q_segdir' SET level=? WHERE level=-1"
+
   };
   int rc = SQLITE_OK;
   sqlite3_stmt *pStmt;
@@ -489,37 +505,30 @@ static void fts3SqlExec(
 
 
 /*
-** This function ensures that the caller has obtained a shared-cache
-** table-lock on the %_content table. This is required before reading
-** data from the fts3 table. If this lock is not acquired first, then
-** the caller may end up holding read-locks on the %_segments and %_segdir
-** tables, but no read-lock on the %_content table. If this happens 
-** a second connection will be able to write to the fts3 table, but
-** attempting to commit those writes might return SQLITE_LOCKED or
-** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain 
-** write-locks on the %_segments and %_segdir ** tables). 
-**
-** We try to avoid this because if FTS3 returns any error when committing
-** a transaction, the whole transaction will be rolled back. And this is
-** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can
-** still happen if the user reads data directly from the %_segments or
-** %_segdir tables instead of going through FTS3 though.
+** This function ensures that the caller has obtained an exclusive 
+** shared-cache table-lock on the %_segdir table. This is required before 
+** writing data to the fts3 table. If this lock is not acquired first, then
+** the caller may end up attempting to take this lock as part of committing
+** a transaction, causing SQLite to return SQLITE_LOCKED or 
+** LOCKED_SHAREDCACHEto a COMMIT command.
 **
-** This reasoning does not apply to a content=xxx table.
+** It is best to avoid this because if FTS3 returns any error when 
+** committing a transaction, the whole transaction will be rolled back. 
+** And this is not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. 
+** It can still happen if the user locks the underlying tables directly 
+** instead of accessing them via FTS.
 */
-int sqlite3Fts3ReadLock(Fts3Table *p){
-  int rc;                         /* Return code */
-  sqlite3_stmt *pStmt;            /* Statement used to obtain lock */
-
-  if( p->zContentTbl==0 ){
-    rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0);
+static int fts3Writelock(Fts3Table *p){
+  int rc = SQLITE_OK;
+  
+  if( p->nPendingData==0 ){
+    sqlite3_stmt *pStmt;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pStmt, 0);
     if( rc==SQLITE_OK ){
       sqlite3_bind_null(pStmt, 1);
       sqlite3_step(pStmt);
       rc = sqlite3_reset(pStmt);
     }
-  }else{
-    rc = SQLITE_OK;
   }
 
   return rc;
@@ -907,12 +916,15 @@ static int fts3InsertTerms(
 ){
   int i;                          /* Iterator variable */
   for(i=2; i<p->nColumn+2; i++){
-    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
-    int rc = fts3PendingTermsAdd(p, iLangid, zText, i-2, &aSz[i-2]);
-    if( rc!=SQLITE_OK ){
-      return rc;
+    int iCol = i-2;
+    if( p->abNotindexed[iCol]==0 ){
+      const char *zText = (const char *)sqlite3_value_text(apVal[i]);
+      int rc = fts3PendingTermsAdd(p, iLangid, zText, iCol, &aSz[iCol]);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
     }
-    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
   }
   return SQLITE_OK;
 }
@@ -1059,9 +1071,12 @@ static void fts3DeleteTerms(
       int iLangid = langidFromSelect(p, pSelect);
       rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pSelect, 0));
       for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
-        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
-        rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[i-1]);
-        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
+        int iCol = i-1;
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
+          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
+        }
       }
       if( rc!=SQLITE_OK ){
         sqlite3_reset(pSelect);
@@ -1345,8 +1360,8 @@ static int fts3SegReaderNext(
   
   /* Because of the FTS3_NODE_PADDING bytes of padding, the following is 
   ** safe (no risk of overread) even if the node data is corrupted. */
-  pNext += sqlite3Fts3GetVarint32(pNext, &nPrefix);
-  pNext += sqlite3Fts3GetVarint32(pNext, &nSuffix);
+  pNext += fts3GetVarint32(pNext, &nPrefix);
+  pNext += fts3GetVarint32(pNext, &nSuffix);
   if( nPrefix<0 || nSuffix<=0 
    || &pNext[nSuffix]>&pReader->aNode[pReader->nNode] 
   ){
@@ -1369,7 +1384,7 @@ static int fts3SegReaderNext(
   memcpy(&pReader->zTerm[nPrefix], pNext, nSuffix);
   pReader->nTerm = nPrefix+nSuffix;
   pNext += nSuffix;
-  pNext += sqlite3Fts3GetVarint32(pNext, &pReader->nDoclist);
+  pNext += fts3GetVarint32(pNext, &pReader->nDoclist);
   pReader->aDoclist = pNext;
   pReader->pOffsetList = 0;
 
@@ -1462,7 +1477,7 @@ static int fts3SegReaderNextDocid(
       /* The following line of code (and the "p++" below the while() loop) is
       ** normally all that is required to move pointer p to the desired 
       ** position. The exception is if this node is being loaded from disk
-      ** incrementally and pointer "p" now points to the first byte passed
+      ** incrementally and pointer "p" now points to the first byte past
       ** the populated part of pReader->aNode[].
       */
       while( *p | c ) c = *p++ & 0x80;
@@ -1911,6 +1926,7 @@ static int fts3WriteSegdir(
   sqlite3_int64 iStartBlock,      /* Value for "start_block" field */
   sqlite3_int64 iLeafEndBlock,    /* Value for "leaves_end_block" field */
   sqlite3_int64 iEndBlock,        /* Value for "end_block" field */
+  sqlite3_int64 nLeafData,        /* Bytes of leaf data in segment */
   char *zRoot,                    /* Blob value for "root" field */
   int nRoot                       /* Number of bytes in buffer zRoot */
 ){
@@ -1921,7 +1937,13 @@ static int fts3WriteSegdir(
     sqlite3_bind_int(pStmt, 2, iIdx);
     sqlite3_bind_int64(pStmt, 3, iStartBlock);
     sqlite3_bind_int64(pStmt, 4, iLeafEndBlock);
-    sqlite3_bind_int64(pStmt, 5, iEndBlock);
+    if( nLeafData==0 ){
+      sqlite3_bind_int64(pStmt, 5, iEndBlock);
+    }else{
+      char *zEnd = sqlite3_mprintf("%lld %lld", iEndBlock, nLeafData);
+      if( !zEnd ) return SQLITE_NOMEM;
+      sqlite3_bind_text(pStmt, 5, zEnd, -1, sqlite3_free);
+    }
     sqlite3_bind_blob(pStmt, 6, zRoot, nRoot, SQLITE_STATIC);
     sqlite3_step(pStmt);
     rc = sqlite3_reset(pStmt);
@@ -2247,6 +2269,9 @@ static int fts3SegWriterAdd(
       nDoclist;                             /* Doclist data */
   }
 
+  /* Increase the total number of bytes written to account for the new entry. */
+  pWriter->nLeafData += nReq;
+
   /* If the buffer currently allocated is too small for this entry, realloc
   ** the buffer to make it large enough.
   */
@@ -2318,13 +2343,13 @@ static int fts3SegWriterFlush(
           pWriter->iFirst, pWriter->iFree, &iLast, &zRoot, &nRoot);
     }
     if( rc==SQLITE_OK ){
-      rc = fts3WriteSegdir(
-          p, iLevel, iIdx, pWriter->iFirst, iLastLeaf, iLast, zRoot, nRoot);
+      rc = fts3WriteSegdir(p, iLevel, iIdx, 
+          pWriter->iFirst, iLastLeaf, iLast, pWriter->nLeafData, zRoot, nRoot);
     }
   }else{
     /* The entire tree fits on the root node. Write it to the segdir table. */
-    rc = fts3WriteSegdir(
-        p, iLevel, iIdx, 0, 0, 0, pWriter->aData, pWriter->nData);
+    rc = fts3WriteSegdir(p, iLevel, iIdx, 
+        0, 0, 0, pWriter->nLeafData, pWriter->aData, pWriter->nData);
   }
   p->nLeafAdd++;
   return rc;
@@ -2409,6 +2434,37 @@ static int fts3SegmentMaxLevel(
 }
 
 /*
+** iAbsLevel is an absolute level that may be assumed to exist within
+** the database. This function checks if it is the largest level number
+** within its index. Assuming no error occurs, *pbMax is set to 1 if
+** iAbsLevel is indeed the largest level, or 0 otherwise, and SQLITE_OK
+** is returned. If an error occurs, an error code is returned and the
+** final value of *pbMax is undefined.
+*/
+static int fts3SegmentIsMaxLevel(Fts3Table *p, i64 iAbsLevel, int *pbMax){
+
+  /* Set pStmt to the compiled version of:
+  **
+  **   SELECT max(level) FROM %Q.'%q_segdir' WHERE level BETWEEN ? AND ?
+  **
+  ** (1024 is actually the value of macro FTS3_SEGDIR_PREFIXLEVEL_STR).
+  */
+  sqlite3_stmt *pStmt;
+  int rc = fts3SqlStmt(p, SQL_SELECT_SEGDIR_MAX_LEVEL, &pStmt, 0);
+  if( rc!=SQLITE_OK ) return rc;
+  sqlite3_bind_int64(pStmt, 1, iAbsLevel+1);
+  sqlite3_bind_int64(pStmt, 2, 
+      ((iAbsLevel/FTS3_SEGDIR_MAXLEVEL)+1) * FTS3_SEGDIR_MAXLEVEL
+  );
+
+  *pbMax = 0;
+  if( SQLITE_ROW==sqlite3_step(pStmt) ){
+    *pbMax = sqlite3_column_type(pStmt, 0)==SQLITE_NULL;
+  }
+  return sqlite3_reset(pStmt);
+}
+
+/*
 ** Delete all entries in the %_segments table associated with the segment
 ** opened with seg-reader pSeg. This function does not affect the contents
 ** of the %_segdir table.
@@ -2530,7 +2586,7 @@ static void fts3ColumnFilter(
       break;
     }
     p = &pList[1];
-    p += sqlite3Fts3GetVarint32(p, &iCurrent);
+    p += fts3GetVarint32(p, &iCurrent);
   }
 
   if( bZero && &pList[nList]!=pEnd ){
@@ -2849,8 +2905,8 @@ int sqlite3Fts3SegReaderStep(
       fts3SegReaderSort(apSegment, nMerge, nMerge, xCmp);
       while( apSegment[0]->pOffsetList ){
         int j;                    /* Number of segments that share a docid */
-        char *pList;
-        int nList;
+        char *pList = 0;
+        int nList = 0;
         int nByte;
         sqlite3_int64 iDocid = apSegment[0]->iDocid;
         fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);
@@ -2944,6 +3000,140 @@ void sqlite3Fts3SegReaderFinish(
 }
 
 /*
+** Decode the "end_block" field, selected by column iCol of the SELECT 
+** statement passed as the first argument. 
+**
+** The "end_block" field may contain either an integer, or a text field
+** containing the text representation of two non-negative integers separated 
+** by one or more space (0x20) characters. In the first case, set *piEndBlock 
+** to the integer value and *pnByte to zero before returning. In the second, 
+** set *piEndBlock to the first value and *pnByte to the second.
+*/
+static void fts3ReadEndBlockField(
+  sqlite3_stmt *pStmt, 
+  int iCol, 
+  i64 *piEndBlock,
+  i64 *pnByte
+){
+  const unsigned char *zText = sqlite3_column_text(pStmt, iCol);
+  if( zText ){
+    int i;
+    int iMul = 1;
+    i64 iVal = 0;
+    for(i=0; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
+    }
+    *piEndBlock = iVal;
+    while( zText[i]==' ' ) i++;
+    iVal = 0;
+    if( zText[i]=='-' ){
+      i++;
+      iMul = -1;
+    }
+    for(/* no-op */; zText[i]>='0' && zText[i]<='9'; i++){
+      iVal = iVal*10 + (zText[i] - '0');
+    }
+    *pnByte = (iVal * (i64)iMul);
+  }
+}
+
+
+/*
+** A segment of size nByte bytes has just been written to absolute level
+** iAbsLevel. Promote any segments that should be promoted as a result.
+*/
+static int fts3PromoteSegments(
+  Fts3Table *p,                   /* FTS table handle */
+  sqlite3_int64 iAbsLevel,        /* Absolute level just updated */
+  sqlite3_int64 nByte             /* Size of new segment at iAbsLevel */
+){
+  int rc = SQLITE_OK;
+  sqlite3_stmt *pRange;
+
+  rc = fts3SqlStmt(p, SQL_SELECT_LEVEL_RANGE2, &pRange, 0);
+
+  if( rc==SQLITE_OK ){
+    int bOk = 0;
+    i64 iLast = (iAbsLevel/FTS3_SEGDIR_MAXLEVEL + 1) * FTS3_SEGDIR_MAXLEVEL - 1;
+    i64 nLimit = (nByte*3)/2;
+
+    /* Loop through all entries in the %_segdir table corresponding to 
+    ** segments in this index on levels greater than iAbsLevel. If there is
+    ** at least one such segment, and it is possible to determine that all 
+    ** such segments are smaller than nLimit bytes in size, they will be 
+    ** promoted to level iAbsLevel.  */
+    sqlite3_bind_int64(pRange, 1, iAbsLevel+1);
+    sqlite3_bind_int64(pRange, 2, iLast);
+    while( SQLITE_ROW==sqlite3_step(pRange) ){
+      i64 nSize = 0, dummy;
+      fts3ReadEndBlockField(pRange, 2, &dummy, &nSize);
+      if( nSize<=0 || nSize>nLimit ){
+        /* If nSize==0, then the %_segdir.end_block field does not not 
+        ** contain a size value. This happens if it was written by an
+        ** old version of FTS. In this case it is not possible to determine
+        ** the size of the segment, and so segment promotion does not
+        ** take place.  */
+        bOk = 0;
+        break;
+      }
+      bOk = 1;
+    }
+    rc = sqlite3_reset(pRange);
+
+    if( bOk ){
+      int iIdx = 0;
+      sqlite3_stmt *pUpdate1;
+      sqlite3_stmt *pUpdate2;
+
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL_IDX, &pUpdate1, 0);
+      }
+      if( rc==SQLITE_OK ){
+        rc = fts3SqlStmt(p, SQL_UPDATE_LEVEL, &pUpdate2, 0);
+      }
+
+      if( rc==SQLITE_OK ){
+
+        /* Loop through all %_segdir entries for segments in this index with
+        ** levels equal to or greater than iAbsLevel. As each entry is visited,
+        ** updated it to set (level = -1) and (idx = N), where N is 0 for the
+        ** oldest segment in the range, 1 for the next oldest, and so on.
+        **
+        ** In other words, move all segments being promoted to level -1,
+        ** setting the "idx" fields as appropriate to keep them in the same
+        ** order. The contents of level -1 (which is never used, except
+        ** transiently here), will be moved back to level iAbsLevel below.  */
+        sqlite3_bind_int64(pRange, 1, iAbsLevel);
+        while( SQLITE_ROW==sqlite3_step(pRange) ){
+          sqlite3_bind_int(pUpdate1, 1, iIdx++);
+          sqlite3_bind_int(pUpdate1, 2, sqlite3_column_int(pRange, 0));
+          sqlite3_bind_int(pUpdate1, 3, sqlite3_column_int(pRange, 1));
+          sqlite3_step(pUpdate1);
+          rc = sqlite3_reset(pUpdate1);
+          if( rc!=SQLITE_OK ){
+            sqlite3_reset(pRange);
+            break;
+          }
+        }
+      }
+      if( rc==SQLITE_OK ){
+        rc = sqlite3_reset(pRange);
+      }
+
+      /* Move level -1 to level iAbsLevel */
+      if( rc==SQLITE_OK ){
+        sqlite3_bind_int64(pUpdate2, 1, iAbsLevel);
+        sqlite3_step(pUpdate2);
+        rc = sqlite3_reset(pUpdate2);
+      }
+    }
+  }
+
+
+  return rc;
+}
+
+/*
 ** Merge all level iLevel segments in the database into a single 
 ** iLevel+1 segment. Or, if iLevel<0, merge all segments into a
 ** single segment with a level equal to the numerically largest level 
@@ -2967,6 +3157,7 @@ static int fts3SegmentMerge(
   Fts3SegFilter filter;           /* Segment term filter condition */
   Fts3MultiSegReader csr;         /* Cursor to iterate through level(s) */
   int bIgnoreEmpty = 0;           /* True to ignore empty segments */
+  i64 iMaxLevel = 0;              /* Max level number for this index/langid */
 
   assert( iLevel==FTS3_SEGCURSOR_ALL
        || iLevel==FTS3_SEGCURSOR_PENDING
@@ -2978,6 +3169,11 @@ static int fts3SegmentMerge(
   rc = sqlite3Fts3SegReaderCursor(p, iLangid, iIndex, iLevel, 0, 0, 1, 0, &csr);
   if( rc!=SQLITE_OK || csr.nSegment==0 ) goto finished;
 
+  if( iLevel!=FTS3_SEGCURSOR_PENDING ){
+    rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iMaxLevel);
+    if( rc!=SQLITE_OK ) goto finished;
+  }
+
   if( iLevel==FTS3_SEGCURSOR_ALL ){
     /* This call is to merge all segments in the database to a single
     ** segment. The level of the new segment is equal to the numerically
@@ -2987,21 +3183,21 @@ static int fts3SegmentMerge(
       rc = SQLITE_DONE;
       goto finished;
     }
-    rc = fts3SegmentMaxLevel(p, iLangid, iIndex, &iNewLevel);
+    iNewLevel = iMaxLevel;
     bIgnoreEmpty = 1;
 
-  }else if( iLevel==FTS3_SEGCURSOR_PENDING ){
-    iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, 0);
-    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, 0, &iIdx);
   }else{
     /* This call is to merge all segments at level iLevel. find the next
     ** available segment index at level iLevel+1. The call to
     ** fts3AllocateSegdirIdx() will merge the segments at level iLevel+1 to 
     ** a single iLevel+2 segment if necessary.  */
-    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
+    assert( FTS3_SEGCURSOR_PENDING==-1 );
     iNewLevel = getAbsoluteLevel(p, iLangid, iIndex, iLevel+1);
+    rc = fts3AllocateSegdirIdx(p, iLangid, iIndex, iLevel+1, &iIdx);
+    bIgnoreEmpty = (iLevel!=FTS3_SEGCURSOR_PENDING) && (iNewLevel>iMaxLevel);
   }
   if( rc!=SQLITE_OK ) goto finished;
+
   assert( csr.nSegment>0 );
   assert( iNewLevel>=getAbsoluteLevel(p, iLangid, iIndex, 0) );
   assert( iNewLevel<getAbsoluteLevel(p, iLangid, iIndex,FTS3_SEGDIR_MAXLEVEL) );
@@ -3018,7 +3214,7 @@ static int fts3SegmentMerge(
         csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
   }
   if( rc!=SQLITE_OK ) goto finished;
-  assert( pWriter );
+  assert( pWriter || bIgnoreEmpty );
 
   if( iLevel!=FTS3_SEGCURSOR_PENDING ){
     rc = fts3DeleteSegdir(
@@ -3026,7 +3222,14 @@ static int fts3SegmentMerge(
     );
     if( rc!=SQLITE_OK ) goto finished;
   }
-  rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);
+  if( pWriter ){
+    rc = fts3SegWriterFlush(p, pWriter, iNewLevel, iIdx);
+    if( rc==SQLITE_OK ){
+      if( iLevel==FTS3_SEGCURSOR_PENDING || iNewLevel<iMaxLevel ){
+        rc = fts3PromoteSegments(p, iNewLevel, pWriter->nLeafData);
+      }
+    }
+  }
 
  finished:
   fts3SegWriterFree(pWriter);
@@ -3036,7 +3239,7 @@ static int fts3SegmentMerge(
 
 
 /* 
-** Flush the contents of pendingTerms to level 0 segments.
+** Flush the contents of pendingTerms to level 0 segments. 
 */
 int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
   int rc = SQLITE_OK;
@@ -3052,14 +3255,19 @@ int sqlite3Fts3PendingTermsFlush(Fts3Table *p){
   ** estimate the number of leaf blocks of content to be written
   */
   if( rc==SQLITE_OK && p->bHasStat
-   && p->bAutoincrmerge==0xff && p->nLeafAdd>0
+   && p->nAutoincrmerge==0xff && p->nLeafAdd>0
   ){
     sqlite3_stmt *pStmt = 0;
     rc = fts3SqlStmt(p, SQL_SELECT_STAT, &pStmt, 0);
     if( rc==SQLITE_OK ){
       sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
       rc = sqlite3_step(pStmt);
-      p->bAutoincrmerge = (rc==SQLITE_ROW && sqlite3_column_int(pStmt, 0));
+      if( rc==SQLITE_ROW ){
+        p->nAutoincrmerge = sqlite3_column_int(pStmt, 0);
+        if( p->nAutoincrmerge==1 ) p->nAutoincrmerge = 8;
+      }else if( rc==SQLITE_DONE ){
+        p->nAutoincrmerge = 0;
+      }
       rc = sqlite3_reset(pStmt);
     }
   }
@@ -3303,9 +3511,11 @@ static int fts3DoRebuild(Fts3Table *p){
       rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pStmt, 0));
       memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
-        const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
-        rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
-        aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        if( p->abNotindexed[iCol]==0 ){
+          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
+          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        }
       }
       if( p->bHasDocsize ){
         fts3InsertDocsize(&rc, p, aSz);
@@ -3425,6 +3635,8 @@ struct IncrmergeWriter {
   int iIdx;                       /* Index of *output* segment in iAbsLevel+1 */
   sqlite3_int64 iStart;           /* Block number of first allocated block */
   sqlite3_int64 iEnd;             /* Block number of last allocated block */
+  sqlite3_int64 nLeafData;        /* Bytes of leaf page data so far */
+  u8 bNoLeafData;                 /* If true, store 0 for segment size */
   NodeWriter aNodeWriter[FTS_MAX_APPENDABLE_HEIGHT];
 };
 
@@ -3493,9 +3705,9 @@ static int nodeReaderNext(NodeReader *p){
     p->aNode = 0;
   }else{
     if( bFirst==0 ){
-      p->iOff += sqlite3Fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);
+      p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nPrefix);
     }
-    p->iOff += sqlite3Fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);
+    p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &nSuffix);
 
     blobGrowBuffer(&p->term, nPrefix+nSuffix, &rc);
     if( rc==SQLITE_OK ){
@@ -3503,7 +3715,7 @@ static int nodeReaderNext(NodeReader *p){
       p->term.n = nPrefix+nSuffix;
       p->iOff += nSuffix;
       if( p->iChild==0 ){
-        p->iOff += sqlite3Fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);
+        p->iOff += fts3GetVarint32(&p->aNode[p->iOff], &p->nDoclist);
         p->aDoclist = &p->aNode[p->iOff];
         p->iOff += p->nDoclist;
       }
@@ -3763,8 +3975,8 @@ static int fts3IncrmergeAppend(
     nSpace += sqlite3Fts3VarintLen(nDoclist) + nDoclist;
   }
 
+  pWriter->nLeafData += nSpace;
   blobGrowBuffer(&pLeaf->block, pLeaf->block.n + nSpace, &rc);
-
   if( rc==SQLITE_OK ){
     if( pLeaf->block.n==0 ){
       pLeaf->block.n = 1;
@@ -3863,6 +4075,7 @@ static void fts3IncrmergeRelease(
         pWriter->iStart,                    /* start_block */
         pWriter->aNodeWriter[0].iBlock,     /* leaves_end_block */
         pWriter->iEnd,                      /* end_block */
+        (pWriter->bNoLeafData==0 ? pWriter->nLeafData : 0),   /* end_block */
         pRoot->block.a, pRoot->block.n      /* root */
     );
   }
@@ -3964,7 +4177,11 @@ static int fts3IncrmergeLoad(
     if( sqlite3_step(pSelect)==SQLITE_ROW ){
       iStart = sqlite3_column_int64(pSelect, 1);
       iLeafEnd = sqlite3_column_int64(pSelect, 2);
-      iEnd = sqlite3_column_int64(pSelect, 3);
+      fts3ReadEndBlockField(pSelect, 3, &iEnd, &pWriter->nLeafData);
+      if( pWriter->nLeafData<0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
+      pWriter->bNoLeafData = (pWriter->nLeafData==0);
       nRoot = sqlite3_column_bytes(pSelect, 4);
       aRoot = sqlite3_column_blob(pSelect, 4);
     }else{
@@ -4555,7 +4772,7 @@ static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){
 
   pHint->n = i;
   i += sqlite3Fts3GetVarint(&pHint->a[i], piAbsLevel);
-  i += sqlite3Fts3GetVarint32(&pHint->a[i], pnInput);
+  i += fts3GetVarint32(&pHint->a[i], pnInput);
   if( i!=nHint ) return SQLITE_CORRUPT_VTAB;
 
   return SQLITE_OK;
@@ -4565,11 +4782,11 @@ static int fts3IncrmergeHintPop(Blob *pHint, i64 *piAbsLevel, int *pnInput){
 /*
 ** Attempt an incremental merge that writes nMerge leaf blocks.
 **
-** Incremental merges happen nMin segments at a time. The two
-** segments to be merged are the nMin oldest segments (the ones with
-** the smallest indexes) in the highest level that contains at least
-** nMin segments. Multiple merges might occur in an attempt to write the 
-** quota of nMerge leaf blocks.
+** Incremental merges happen nMin segments at a time. The segments 
+** to be merged are the nMin oldest segments (the ones with the smallest 
+** values for the _segdir.idx field) in the highest level that contains 
+** at least nMin segments. Multiple merges might occur in an attempt to 
+** write the quota of nMerge leaf blocks.
 */
 int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
   int rc;                         /* Return code */
@@ -4594,6 +4811,7 @@ int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
     const i64 nMod = FTS3_SEGDIR_MAXLEVEL * p->nIndex;
     sqlite3_stmt *pFindLevel = 0; /* SQL used to determine iAbsLevel */
     int bUseHint = 0;             /* True if attempting to append */
+    int iIdx = 0;                 /* Largest idx in level (iAbsLevel+1) */
 
     /* Search the %_segdir table for the absolute level with the smallest
     ** relative level number that contains at least nMin segments, if any.
@@ -4647,6 +4865,19 @@ int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
     ** to start work on some other level.  */
     memset(pWriter, 0, nAlloc);
     pFilter->flags = FTS3_SEGMENT_REQUIRE_POS;
+
+    if( rc==SQLITE_OK ){
+      rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);
+      assert( bUseHint==1 || bUseHint==0 );
+      if( iIdx==0 || (bUseHint && iIdx==1) ){
+        int bIgnore = 0;
+        rc = fts3SegmentIsMaxLevel(p, iAbsLevel+1, &bIgnore);
+        if( bIgnore ){
+          pFilter->flags |= FTS3_SEGMENT_IGNORE_EMPTY;
+        }
+      }
+    }
+
     if( rc==SQLITE_OK ){
       rc = fts3IncrmergeCsr(p, iAbsLevel, nSeg, pCsr);
     }
@@ -4654,16 +4885,12 @@ int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
      && SQLITE_OK==(rc = sqlite3Fts3SegReaderStart(p, pCsr, pFilter))
      && SQLITE_ROW==(rc = sqlite3Fts3SegReaderStep(p, pCsr))
     ){
-      int iIdx = 0;               /* Largest idx in level (iAbsLevel+1) */
-      rc = fts3IncrmergeOutputIdx(p, iAbsLevel, &iIdx);
-      if( rc==SQLITE_OK ){
-        if( bUseHint && iIdx>0 ){
-          const char *zKey = pCsr->zTerm;
-          int nKey = pCsr->nTerm;
-          rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);
-        }else{
-          rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);
-        }
+      if( bUseHint && iIdx>0 ){
+        const char *zKey = pCsr->zTerm;
+        int nKey = pCsr->nTerm;
+        rc = fts3IncrmergeLoad(p, iAbsLevel, iIdx-1, zKey, nKey, pWriter);
+      }else{
+        rc = fts3IncrmergeWriter(p, iAbsLevel, iIdx, pCsr, pWriter);
       }
 
       if( rc==SQLITE_OK && pWriter->nLeafEst ){
@@ -4685,7 +4912,13 @@ int sqlite3Fts3Incrmerge(Fts3Table *p, int nMerge, int nMin){
         }
       }
 
+      if( nSeg!=0 ){
+        pWriter->nLeafData = pWriter->nLeafData * -1;
+      }
       fts3IncrmergeRelease(p, pWriter, &rc);
+      if( nSeg==0 && pWriter->bNoLeafData==0 ){
+        fts3PromoteSegments(p, iAbsLevel+1, pWriter->nLeafData);
+      }
     }
 
     sqlite3Fts3SegReaderFinish(pCsr);
@@ -4772,16 +5005,19 @@ static int fts3DoAutoincrmerge(
 ){
   int rc = SQLITE_OK;
   sqlite3_stmt *pStmt = 0;
-  p->bAutoincrmerge = fts3Getint(&zParam)!=0;
+  p->nAutoincrmerge = fts3Getint(&zParam);
+  if( p->nAutoincrmerge==1 || p->nAutoincrmerge>FTS3_MERGE_COUNT ){
+    p->nAutoincrmerge = 8;
+  }
   if( !p->bHasStat ){
     assert( p->bFts4==0 );
     sqlite3Fts3CreateStatTable(&rc, p);
     if( rc ) return rc;
   }
   rc = fts3SqlStmt(p, SQL_REPLACE_STAT, &pStmt, 0);
-  if( rc ) return rc;;
+  if( rc ) return rc;
   sqlite3_bind_int(pStmt, 1, FTS_STAT_AUTOINCRMERGE);
-  sqlite3_bind_int(pStmt, 2, p->bAutoincrmerge);
+  sqlite3_bind_int(pStmt, 2, p->nAutoincrmerge);
   sqlite3_step(pStmt);
   rc = sqlite3_reset(pStmt);
   return rc;
@@ -4938,34 +5174,36 @@ static int fts3IntegrityCheck(Fts3Table *p, int *pbOk){
       int iCol;
 
       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
-        const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
-        int nText = sqlite3_column_bytes(pStmt, iCol+1);
-        sqlite3_tokenizer_cursor *pT = 0;
-
-        rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText, &pT);
-        while( rc==SQLITE_OK ){
-          char const *zToken;       /* Buffer containing token */
-          int nToken = 0;           /* Number of bytes in token */
-          int iDum1 = 0, iDum2 = 0; /* Dummy variables */
-          int iPos = 0;             /* Position of token in zText */
-
-          rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);
-          if( rc==SQLITE_OK ){
-            int i;
-            cksum2 = cksum2 ^ fts3ChecksumEntry(
-                zToken, nToken, iLang, 0, iDocid, iCol, iPos
-            );
-            for(i=1; i<p->nIndex; i++){
-              if( p->aIndex[i].nPrefix<=nToken ){
-                cksum2 = cksum2 ^ fts3ChecksumEntry(
-                  zToken, p->aIndex[i].nPrefix, iLang, i, iDocid, iCol, iPos
-                );
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pStmt, iCol+1);
+          int nText = sqlite3_column_bytes(pStmt, iCol+1);
+          sqlite3_tokenizer_cursor *pT = 0;
+
+          rc = sqlite3Fts3OpenTokenizer(p->pTokenizer, iLang, zText, nText,&pT);
+          while( rc==SQLITE_OK ){
+            char const *zToken;       /* Buffer containing token */
+            int nToken = 0;           /* Number of bytes in token */
+            int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+            int iPos = 0;             /* Position of token in zText */
+
+            rc = pModule->xNext(pT, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+            if( rc==SQLITE_OK ){
+              int i;
+              cksum2 = cksum2 ^ fts3ChecksumEntry(
+                  zToken, nToken, iLang, 0, iDocid, iCol, iPos
+              );
+              for(i=1; i<p->nIndex; i++){
+                if( p->aIndex[i].nPrefix<=nToken ){
+                  cksum2 = cksum2 ^ fts3ChecksumEntry(
+                      zToken, p->aIndex[i].nPrefix, iLang, i, iDocid, iCol, iPos
+                  );
+                }
               }
             }
           }
+          if( pT ) pModule->xClose(pT);
+          if( rc==SQLITE_DONE ) rc = SQLITE_OK;
         }
-        if( pT ) pModule->xClose(pT);
-        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
       }
     }
 
@@ -5049,6 +5287,9 @@ static int fts3SpecialInsert(Fts3Table *p, sqlite3_value *pVal){
   }else if( nVal>11 && 0==sqlite3_strnicmp(zVal, "maxpending=", 9) ){
     p->nMaxPendingData = atoi(&zVal[11]);
     rc = SQLITE_OK;
+  }else if( nVal>21 && 0==sqlite3_strnicmp(zVal, "test-no-incr-doclist=", 21) ){
+    p->bNoIncrDoclist = atoi(&zVal[21]);
+    rc = SQLITE_OK;
 #endif
   }else{
     rc = SQLITE_ERROR;
@@ -5108,32 +5349,34 @@ int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){
     iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
   
     for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
-      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
-      sqlite3_tokenizer_cursor *pTC = 0;
-  
-      rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
-      while( rc==SQLITE_OK ){
-        char const *zToken;       /* Buffer containing token */
-        int nToken = 0;           /* Number of bytes in token */
-        int iDum1 = 0, iDum2 = 0; /* Dummy variables */
-        int iPos = 0;             /* Position of token in zText */
-  
-        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
-        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
-          Fts3PhraseToken *pPT = pDef->pToken;
-          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
-           && (pPT->bFirst==0 || iPos==0)
-           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
-           && (0==memcmp(zToken, pPT->z, pPT->n))
-          ){
-            fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+      if( p->abNotindexed[i]==0 ){
+        const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
+        sqlite3_tokenizer_cursor *pTC = 0;
+
+        rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
+        while( rc==SQLITE_OK ){
+          char const *zToken;       /* Buffer containing token */
+          int nToken = 0;           /* Number of bytes in token */
+          int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+          int iPos = 0;             /* Position of token in zText */
+
+          rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+          for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
+            Fts3PhraseToken *pPT = pDef->pToken;
+            if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
+                && (pPT->bFirst==0 || iPos==0)
+                && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
+                && (0==memcmp(zToken, pPT->z, pPT->n))
+              ){
+              fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+            }
           }
         }
+        if( pTC ) pModule->xClose(pTC);
+        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
       }
-      if( pTC ) pModule->xClose(pTC);
-      if( rc==SQLITE_DONE ) rc = SQLITE_OK;
     }
-  
+
     for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
       if( pDef->pList ){
         rc = fts3PendingListAppendVarint(&pDef->pList, 0);
@@ -5265,6 +5508,10 @@ int sqlite3Fts3UpdateMethod(
   int nChng = 0;                  /* Net change in number of documents */
   int bInsertDone = 0;
 
+  /* At this point it must be known if the %_stat table exists or not.
+  ** So bHasStat may not be 2.  */
+  assert( p->bHasStat==0 || p->bHasStat==1 );
+
   assert( p->pSegments==0 );
   assert( 
       nArg==1                     /* DELETE operations */
@@ -5297,6 +5544,9 @@ int sqlite3Fts3UpdateMethod(
   aSzIns = &aSzDel[p->nColumn+1];
   memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);
 
+  rc = fts3Writelock(p);
+  if( rc!=SQLITE_OK ) goto update_out;
+
   /* If this is an INSERT operation, or an UPDATE that modifies the rowid
   ** value, then this operation requires constraint handling.
   **
diff --git a/ext/fts3/tool/fts3view.c b/ext/fts3/tool/fts3view.c
index 479ae98..3dc1ba8 100644
--- a/ext/fts3/tool/fts3view.c
+++ b/ext/fts3/tool/fts3view.c
@@ -376,7 +376,7 @@ static void showSegmentStats(sqlite3 *db, const char *zTab){
   sqlite3_finalize(pStmt);
   nLeaf = nSeg - nIdx;
   printf("Leaf segments larger than %5d bytes.... %9d   %5.2f%%\n",
-         pgsz-45, n, n*100.0/nLeaf);
+         pgsz-45, n, nLeaf>0 ? n*100.0/nLeaf : 0.0);
 
   pStmt = prepare(db, "SELECT max(level%%1024) FROM '%q_segdir'", zTab);
   mxLevel = 0;
@@ -554,7 +554,7 @@ static void decodeSegment(
   sqlite3_int64 n;
   sqlite3_int64 iDocsz;
   int iHeight;
-  int i = 0;
+  sqlite3_int64 i = 0;
   int cnt = 0;
   char zTerm[1000];
 
@@ -576,12 +576,12 @@ static void decodeSegment(
       fprintf(stderr, "term to long\n");
       exit(1);
     }
-    memcpy(zTerm+iPrefix, aData+i, nTerm);
+    memcpy(zTerm+iPrefix, aData+i, (size_t)nTerm);
     zTerm[iPrefix+nTerm] = 0;
     i += nTerm;
     if( iHeight==0 ){
       i += getVarint(aData+i, &iDocsz);
-      printf("term: %-25s doclist %7lld bytes offset %d\n", zTerm, iDocsz, i);
+      printf("term: %-25s doclist %7lld bytes offset %lld\n", zTerm, iDocsz, i);
       i += iDocsz;
     }else{
       printf("term: %-25s child %lld\n", zTerm, ++iChild);
@@ -749,18 +749,19 @@ static void decodeDoclist(
 */
 static void showDoclist(sqlite3 *db, const char *zTab){
   const unsigned char *aData;
-  sqlite3_int64 offset, nData;
+  sqlite3_int64 offset;
+  int nData;
   sqlite3_stmt *pStmt;
 
   offset = atoi64(azExtra[1]);
-  nData = atoi64(azExtra[2]);
+  nData = atoi(azExtra[2]);
   pStmt = prepareToGetSegment(db, zTab, azExtra[0]);
   if( sqlite3_step(pStmt)!=SQLITE_ROW ){
     sqlite3_finalize(pStmt);
     return;
   }
   aData = sqlite3_column_blob(pStmt, 0);
-  printf("Doclist at %s offset %lld of size %lld bytes:\n",
+  printf("Doclist at %s offset %lld of size %d bytes:\n",
          azExtra[0], offset, nData);
   if( findOption("raw", 0, 0)!=0 ){
     printBlob(aData+offset, nData);
diff --git a/ext/fts3/unicode/mkunicode.tcl b/ext/fts3/unicode/mkunicode.tcl
index 0d58e8a..c3083ee 100644
--- a/ext/fts3/unicode/mkunicode.tcl
+++ b/ext/fts3/unicode/mkunicode.tcl
@@ -160,7 +160,7 @@ proc print_rd {map} {
   }
   assert( key>=aDia[iRes] );
   return ((c > (aDia[iRes]>>3) + (aDia[iRes]&0x07)) ? c : (int)aChar[iRes]);}
-  puts "\};"
+  puts "\}"
 }
 
 proc print_isdiacritic {zFunc map} {
@@ -239,7 +239,10 @@ proc an_load_unicodedata_text {zName} {
     foreach $lField $fields {}
 
     set iCode [expr "0x$code"]
-    set bAlnum [expr {[lsearch {L N} [string range $general_category 0 0]]>=0}]
+    set bAlnum [expr {
+         [lsearch {L N} [string range $general_category 0 0]] >= 0
+      || $general_category=="Co"
+    }]
 
     if { !$bAlnum } { lappend lRet $iCode }
   }
@@ -295,7 +298,7 @@ proc an_print_range_array {lRange} {
   ** using this format.
   */
   }]
-  puts -nonewline "  const static unsigned int aEntry\[\] = \{"
+  puts -nonewline "  static const unsigned int aEntry\[\] = \{"
   set i 0
   foreach range $lRange {
     foreach {iFirst nRange} $range {}
@@ -346,7 +349,7 @@ proc print_isalnum {zFunc lRange} {
     return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
   }else if( c<(1<<22) ){
     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
-    int iRes;
+    int iRes = 0;
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;
     int iLo = 0;
     while( iHi>=iLo ){
@@ -360,7 +363,7 @@ proc print_isalnum {zFunc lRange} {
     }
     assert( aEntry[0]<key );
     assert( key>=aEntry[iRes] );
-    return (c >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
+    return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
   }
   return 1;}
   puts "\}"
@@ -729,7 +732,7 @@ proc print_fileheader {} {
 */
   }]
   puts ""
-  puts "#if !defined(SQLITE_DISABLE_FTS3_UNICODE)"
+  puts "#ifndef SQLITE_DISABLE_FTS3_UNICODE"
   puts "#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)"
   puts ""
   puts "#include <assert.h>"
diff --git a/ext/icu/icu.c b/ext/icu/icu.c
index ae28d70..1ce1e0c 100644
--- a/ext/icu/icu.c
+++ b/ext/icu/icu.c
@@ -22,7 +22,7 @@
 **   * Implementations of the SQL scalar upper() and lower() functions
 **     for case mapping.
 **
-**   * Integration of ICU and SQLite collation seqences.
+**   * Integration of ICU and SQLite collation sequences.
 **
 **   * An implementation of the LIKE operator that uses ICU to 
 **     provide case-independent matching.
@@ -488,7 +488,10 @@ int sqlite3IcuInit(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_icu_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/ext/misc/amatch.c b/ext/misc/amatch.c
index b613080..d869dbd 100644
--- a/ext/misc/amatch.c
+++ b/ext/misc/amatch.c
@@ -786,6 +786,7 @@ static void amatchFree(amatch_vtab *p){
     sqlite3_free(p->zVocabTab);
     sqlite3_free(p->zVocabWord);
     sqlite3_free(p->zVocabLang);
+    sqlite3_free(p->zSelf);
     memset(p, 0, sizeof(*p));
     sqlite3_free(p);
   }
@@ -948,6 +949,9 @@ static void amatchClearCursor(amatch_cursor *pCur){
   pCur->pAllWords = 0;
   sqlite3_free(pCur->zInput);
   pCur->zInput = 0;
+  sqlite3_free(pCur->zBuf);
+  pCur->zBuf = 0;
+  pCur->nBuf = 0;
   pCur->pCost = 0;
   pCur->pWord = 0;
   pCur->pCurrent = 0;
@@ -1103,7 +1107,7 @@ static int amatchNext(sqlite3_vtab_cursor *cur){
     char *zSql;
     if( p->zVocabLang && p->zVocabLang[0] ){
       zSql = sqlite3_mprintf(
-          "SELECT \"%s\" FROM \"%s\"",
+          "SELECT \"%w\" FROM \"%w\"",
           " WHERE \"%w\">=?1 AND \"%w\"=?2"
           " ORDER BY 1",
           p->zVocabWord, p->zVocabTab,
@@ -1111,7 +1115,7 @@ static int amatchNext(sqlite3_vtab_cursor *cur){
       );
     }else{
       zSql = sqlite3_mprintf(
-          "SELECT \"%s\" FROM \"%s\""
+          "SELECT \"%w\" FROM \"%w\""
           " WHERE \"%w\">=?1"
           " ORDER BY 1",
           p->zVocabWord, p->zVocabTab,
diff --git a/ext/misc/closure.c b/ext/misc/closure.c
index 213b763..30c812d 100644
--- a/ext/misc/closure.c
+++ b/ext/misc/closure.c
@@ -496,7 +496,7 @@ static const char *closureValueOfKey(const char *zKey, const char *zStr){
 /*
 ** xConnect/xCreate method for the closure module. Arguments are:
 **
-**   argv[0]    -> module name  ("approximate_match")
+**   argv[0]    -> module name  ("transitive_closure")
 **   argv[1]    -> database name
 **   argv[2]    -> table name
 **   argv[3...] -> arguments
@@ -826,11 +826,17 @@ static int closureBestIndex(
   int iPlan = 0;
   int i;
   int idx = 1;
+  int seenMatch = 0;
   const struct sqlite3_index_constraint *pConstraint;
   closure_vtab *pVtab = (closure_vtab*)pTab;
+  double rCost = 10000000.0;
 
   pConstraint = pIdxInfo->aConstraint;
   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->iColumn==CLOSURE_COL_ROOT
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      seenMatch = 1;
+    }
     if( pConstraint->usable==0 ) continue;
     if( (iPlan & 1)==0 
      && pConstraint->iColumn==CLOSURE_COL_ROOT
@@ -839,6 +845,7 @@ static int closureBestIndex(
       iPlan |= 1;
       pIdxInfo->aConstraintUsage[i].argvIndex = 1;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 100.0;
     }
     if( (iPlan & 0x0000f0)==0
      && pConstraint->iColumn==CLOSURE_COL_DEPTH
@@ -849,6 +856,7 @@ static int closureBestIndex(
       iPlan |= idx<<4;
       pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
       if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ) iPlan |= 0x000002;
+      rCost /= 5.0;
     }
     if( (iPlan & 0x000f00)==0
      && pConstraint->iColumn==CLOSURE_COL_TABLENAME
@@ -857,6 +865,7 @@ static int closureBestIndex(
       iPlan |= idx<<8;
       pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 5.0;
     }
     if( (iPlan & 0x00f000)==0
      && pConstraint->iColumn==CLOSURE_COL_IDCOLUMN
@@ -891,13 +900,14 @@ static int closureBestIndex(
   ){
     pIdxInfo->orderByConsumed = 1;
   }
-  pIdxInfo->estimatedCost = (double)10000;
+  if( seenMatch && (iPlan&1)==0 ) rCost *= 1e30;
+  pIdxInfo->estimatedCost = rCost;
    
   return SQLITE_OK;
 }
 
 /*
-** A virtual table module that implements the "approximate_match".
+** A virtual table module that implements the "transitive_closure".
 */
 static sqlite3_module closureModule = {
   0,                      /* iVersion */
diff --git a/ext/misc/compress.c b/ext/misc/compress.c
new file mode 100644
index 0000000..a405911
--- /dev/null
+++ b/ext/misc/compress.c
@@ -0,0 +1,107 @@
+/*
+** 2014-06-13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements SQL compression functions
+** compress() and uncompress() using ZLIB.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <zlib.h>
+
+/*
+** Implementation of the "compress(X)" SQL function.  The input X is
+** compressed using zLib and the output is returned.
+**
+** The output is a BLOB that begins with a variable-length integer that
+** is the input size in bytes (the size of X before compression).  The
+** variable-length integer is implemented as 1 to 5 bytes.  There are
+** seven bits per integer stored in the lower seven bits of each byte.
+** More significant bits occur first.  The most significant bit (0x80)
+** is a flag to indicate the end of the integer.
+*/
+static void compressFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *pIn;
+  unsigned char *pOut;
+  unsigned int nIn;
+  unsigned long int nOut;
+  unsigned char x[8];
+  int i, j;
+
+  pIn = sqlite3_value_blob(argv[0]);
+  nIn = sqlite3_value_bytes(argv[0]);
+  nOut = 13 + nIn + (nIn+999)/1000;
+  pOut = sqlite3_malloc( nOut+5 );
+  for(i=4; i>=0; i--){
+    x[i] = (nIn >> (7*(4-i)))&0x7f;
+  }
+  for(i=0; i<4 && x[i]==0; i++){}
+  for(j=0; i<=4; i++, j++) pOut[j] = x[i];
+  pOut[j-1] |= 0x80;
+  compress(&pOut[j], &nOut, pIn, nIn);
+  sqlite3_result_blob(context, pOut, nOut+j, sqlite3_free);
+}
+
+/*
+** Implementation of the "uncompress(X)" SQL function.  The argument X
+** is a blob which was obtained from compress(Y).  The output will be
+** the value Y.
+*/
+static void uncompressFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const unsigned char *pIn;
+  unsigned char *pOut;
+  unsigned int nIn;
+  unsigned long int nOut;
+  int rc;
+  int i;
+
+  pIn = sqlite3_value_blob(argv[0]);
+  nIn = sqlite3_value_bytes(argv[0]);
+  nOut = 0;
+  for(i=0; i<nIn && i<5; i++){
+    nOut = (nOut<<7) | (pIn[i]&0x7f);
+    if( (pIn[i]&0x80)!=0 ){ i++; break; }
+  }
+  pOut = sqlite3_malloc( nOut+1 );
+  rc = uncompress(pOut, &nOut, &pIn[i], nIn-i);
+  if( rc==Z_OK ){
+    sqlite3_result_blob(context, pOut, nOut, sqlite3_free);
+  }
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_compress_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "compress", 1, SQLITE_UTF8, 0,
+                               compressFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "uncompress", 1, SQLITE_UTF8, 0,
+                                 uncompressFunc, 0, 0);
+  }
+  return rc;
+}
diff --git a/ext/misc/fileio.c b/ext/misc/fileio.c
new file mode 100644
index 0000000..fbe2d03
--- /dev/null
+++ b/ext/misc/fileio.c
@@ -0,0 +1,100 @@
+/*
+** 2014-06-13
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements SQL functions readfile() and
+** writefile().
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <stdio.h>
+
+/*
+** Implementation of the "readfile(X)" SQL function.  The entire content
+** of the file named X is read and returned as a BLOB.  NULL is returned
+** if the file does not exist or is unreadable.
+*/
+static void readfileFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  const char *zName;
+  FILE *in;
+  long nIn;
+  void *pBuf;
+
+  zName = (const char*)sqlite3_value_text(argv[0]);
+  if( zName==0 ) return;
+  in = fopen(zName, "rb");
+  if( in==0 ) return;
+  fseek(in, 0, SEEK_END);
+  nIn = ftell(in);
+  rewind(in);
+  pBuf = sqlite3_malloc( nIn );
+  if( pBuf && 1==fread(pBuf, nIn, 1, in) ){
+    sqlite3_result_blob(context, pBuf, nIn, sqlite3_free);
+  }else{
+    sqlite3_free(pBuf);
+  }
+  fclose(in);
+}
+
+/*
+** Implementation of the "writefile(X,Y)" SQL function.  The argument Y
+** is written into file X.  The number of bytes written is returned.  Or
+** NULL is returned if something goes wrong, such as being unable to open
+** file X for writing.
+*/
+static void writefileFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  FILE *out;
+  const char *z;
+  sqlite3_int64 rc;
+  const char *zFile;
+
+  zFile = (const char*)sqlite3_value_text(argv[0]);
+  if( zFile==0 ) return;
+  out = fopen(zFile, "wb");
+  if( out==0 ) return;
+  z = (const char*)sqlite3_value_blob(argv[1]);
+  if( z==0 ){
+    rc = 0;
+  }else{
+    rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out);
+  }
+  fclose(out);
+  sqlite3_result_int64(context, rc);
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fileio_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0,
+                               readfileFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0,
+                                 writefileFunc, 0, 0);
+  }
+  return rc;
+}
diff --git a/ext/misc/fuzzer.c b/ext/misc/fuzzer.c
index 642b8f9..fe41cda 100644
--- a/ext/misc/fuzzer.c
+++ b/ext/misc/fuzzer.c
@@ -1077,9 +1077,16 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   int iDistTerm = -1;
   int iRulesetTerm = -1;
   int i;
+  int seenMatch = 0;
   const struct sqlite3_index_constraint *pConstraint;
+  double rCost = 1e12;
+
   pConstraint = pIdxInfo->aConstraint;
   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->iColumn==0
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+      seenMatch = 1;
+    }
     if( pConstraint->usable==0 ) continue;
     if( (iPlan & 1)==0 
      && pConstraint->iColumn==0
@@ -1088,6 +1095,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       iPlan |= 1;
       pIdxInfo->aConstraintUsage[i].argvIndex = 1;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 1e6;
     }
     if( (iPlan & 2)==0
      && pConstraint->iColumn==1
@@ -1096,6 +1104,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
     ){
       iPlan |= 2;
       iDistTerm = i;
+      rCost /= 10.0;
     }
     if( (iPlan & 4)==0
      && pConstraint->iColumn==2
@@ -1104,6 +1113,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       iPlan |= 4;
       pIdxInfo->aConstraintUsage[i].omit = 1;
       iRulesetTerm = i;
+      rCost /= 10.0;
     }
   }
   if( iPlan & 2 ){
@@ -1122,7 +1132,8 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   ){
     pIdxInfo->orderByConsumed = 1;
   }
-  pIdxInfo->estimatedCost = (double)10000;
+  if( seenMatch && (iPlan&1)==0 ) rCost = 1e99;
+  pIdxInfo->estimatedCost = rCost;
    
   return SQLITE_OK;
 }
diff --git a/ext/misc/ieee754.c b/ext/misc/ieee754.c
index 436b11e..f143893 100644
--- a/ext/misc/ieee754.c
+++ b/ext/misc/ieee754.c
@@ -18,11 +18,11 @@
 **
 ** In the first form, the value X should be a floating-point number.
 ** The function will return a string of the form 'ieee754(Y,Z)' where
-** Y and Z are integers such that X==Y*pow(w.0,Z).
+** Y and Z are integers such that X==Y*pow(2,Z).
 **
 ** In the second form, Y and Z are integers which are the mantissa and
 ** base-2 exponent of a new floating point number.  The function returns
-** a floating-point value equal to Y*pow(2.0,Z).
+** a floating-point value equal to Y*pow(2,Z).
 **
 ** Examples:
 **
diff --git a/ext/misc/nextchar.c b/ext/misc/nextchar.c
index e063043..49dfd24 100644
--- a/ext/misc/nextchar.c
+++ b/ext/misc/nextchar.c
@@ -10,12 +10,22 @@
 **
 ******************************************************************************
 **
-** This file contains code to implement the next_char(A,T,F,W) SQL function.
+** This file contains code to implement the next_char(A,T,F,W,C) SQL function.
 **
-** The next_char(A,T,F,H) function finds all valid "next" characters for
-** string A given the vocabulary in T.F.  The T.F field should be indexed.
-** If the W value exists and is a non-empty string, then it is an SQL
-** expression that limits the entries in T.F that will be considered.
+** The next_char(A,T,F,W,C) function finds all valid "next" characters for
+** string A given the vocabulary in T.F.  If the W value exists and is a
+** non-empty string, then it is an SQL expression that limits the entries
+** in T.F that will be considered.  If C exists and is a non-empty string,
+** then it is the name of the collating sequence to use for comparison.  If
+** 
+** Only the first three arguments are required.  If the C parameter is 
+** omitted or is NULL or is an empty string, then the default collating 
+** sequence of T.F is used for comparision.  If the W parameter is omitted
+** or is NULL or is an empty string, then no filtering of the output is
+** done.
+**
+** The T.F column should be indexed using collation C or else this routine
+** will be quite slow.
 **
 ** For example, suppose an application has a dictionary like this:
 **
@@ -28,6 +38,19 @@
 ** out) run the following query:
 **
 **   SELECT next_char('cha','dictionary','word');
+**
+** IMPLEMENTATION NOTES:
+**
+** The next_char function is implemented using recursive SQL that makes
+** use of the table name and column name as part of a query.  If either
+** the table name or column name are keywords or contain special characters,
+** then they should be escaped.  For example:
+**
+**   SELECT next_char('cha','[dictionary]','[word]');
+**
+** This also means that the table name can be a subquery:
+**
+**   SELECT next_char('cha','(SELECT word AS w FROM dictionary)','w');
 */
 #include "sqlite3ext.h"
 SQLITE_EXTENSION_INIT1
@@ -184,6 +207,9 @@ static void nextCharFunc(
   const unsigned char *zTable = sqlite3_value_text(argv[1]);
   const unsigned char *zField = sqlite3_value_text(argv[2]);
   const unsigned char *zWhere;
+  const unsigned char *zCollName;
+  char *zWhereClause = 0;
+  char *zColl = 0;
   char *zSql;
   int rc;
 
@@ -192,25 +218,41 @@ static void nextCharFunc(
   c.zPrefix = sqlite3_value_text(argv[0]);
   c.nPrefix = sqlite3_value_bytes(argv[0]);
   if( zTable==0 || zField==0 || c.zPrefix==0 ) return;
-  if( argc<4
-   || (zWhere = sqlite3_value_text(argv[3]))==0
-   || zWhere[0]==0
+  if( argc>=4
+   && (zWhere = sqlite3_value_text(argv[3]))!=0
+   && zWhere[0]!=0
+  ){
+    zWhereClause = sqlite3_mprintf("AND (%s)", zWhere);
+    if( zWhereClause==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
+  }else{
+    zWhereClause = "";
+  }
+  if( argc>=5
+   && (zCollName = sqlite3_value_text(argv[4]))!=0
+   && zCollName[0]!=0 
   ){
-    zSql = sqlite3_mprintf(
-        "SELECT \"%w\" FROM \"%w\""
-        " WHERE \"%w\">=(?1 || ?2)"
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
-        " ORDER BY 1 ASC LIMIT 1",
-        zField, zTable, zField, zField);
+    zColl = sqlite3_mprintf("collate \"%w\"", zCollName);
+    if( zColl==0 ){
+      sqlite3_result_error_nomem(context);
+      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+      return;
+    }
   }else{
-    zSql = sqlite3_mprintf(
-        "SELECT \"%w\" FROM \"%w\""
-        " WHERE \"%w\">=(?1 || ?2)"
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
-        "   AND (%s)"
-        " ORDER BY 1 ASC LIMIT 1",
-        zField, zTable, zField, zField, zWhere);
+    zColl = "";
   }
+  zSql = sqlite3_mprintf(
+    "SELECT %s FROM %s"
+    " WHERE %s>=(?1 || ?2) %s"
+    "   AND %s<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
+    "   %s"
+    " ORDER BY 1 %s ASC LIMIT 1",
+    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
+  );
+  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+  if( zColl[0] ) sqlite3_free(zColl);
   if( zSql==0 ){
     sqlite3_result_error_nomem(context);
     return;
@@ -261,5 +303,9 @@ int sqlite3_nextchar_init(
     rc = sqlite3_create_function(db, "next_char", 4, SQLITE_UTF8, 0,
                                  nextCharFunc, 0, 0);
   }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "next_char", 5, SQLITE_UTF8, 0,
+                                 nextCharFunc, 0, 0);
+  }
   return rc;
 }
diff --git a/ext/misc/percentile.c b/ext/misc/percentile.c
new file mode 100644
index 0000000..74a4c9d
--- /dev/null
+++ b/ext/misc/percentile.c
@@ -0,0 +1,219 @@
+/*
+** 2013-05-28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code to implement the percentile(Y,P) SQL function
+** as described below:
+**
+**   (1)  The percentile(Y,P) function is an aggregate function taking
+**        exactly two arguments.
+**
+**   (2)  If the P argument to percentile(Y,P) is not the same for every
+**        row in the aggregate then an error is thrown.  The word "same"
+**        in the previous sentence means that the value differ by less
+**        than 0.001.
+**
+**   (3)  If the P argument to percentile(Y,P) evaluates to anything other
+**        than a number in the range of 0.0 to 100.0 inclusive then an
+**        error is thrown.
+**
+**   (4)  If any Y argument to percentile(Y,P) evaluates to a value that
+**        is not NULL and is not numeric then an error is thrown.
+**
+**   (5)  If any Y argument to percentile(Y,P) evaluates to plus or minus
+**        infinity then an error is thrown.  (SQLite always interprets NaN
+**        values as NULL.)
+**
+**   (6)  Both Y and P in percentile(Y,P) can be arbitrary expressions,
+**        including CASE WHEN expressions.
+**
+**   (7)  The percentile(Y,P) aggregate is able to handle inputs of at least
+**        one million (1,000,000) rows.
+**
+**   (8)  If there are no non-NULL values for Y, then percentile(Y,P)
+**        returns NULL.
+**
+**   (9)  If there is exactly one non-NULL value for Y, the percentile(Y,P)
+**        returns the one Y value.
+**
+**  (10)  If there N non-NULL values of Y where N is two or more and
+**        the Y values are ordered from least to greatest and a graph is
+**        drawn from 0 to N-1 such that the height of the graph at J is
+**        the J-th Y value and such that straight lines are drawn between
+**        adjacent Y values, then the percentile(Y,P) function returns
+**        the height of the graph at P*(N-1)/100.
+**
+**  (11)  The percentile(Y,P) function always returns either a floating
+**        point number or NULL.
+**
+**  (12)  The percentile(Y,P) is implemented as a single C99 source-code
+**        file that compiles into a shared-library or DLL that can be loaded
+**        into SQLite using the sqlite3_load_extension() interface.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* The following object is the session context for a single percentile()
+** function.  We have to remember all input Y values until the very end.
+** Those values are accumulated in the Percentile.a[] array.
+*/
+typedef struct Percentile Percentile;
+struct Percentile {
+  unsigned nAlloc;     /* Number of slots allocated for a[] */
+  unsigned nUsed;      /* Number of slots actually used in a[] */
+  double rPct;         /* 1.0 more than the value for P */
+  double *a;           /* Array of Y values */
+};
+
+/*
+** Return TRUE if the input floating-point number is an infinity.
+*/
+static int isInfinity(double r){
+  sqlite3_uint64 u;
+  assert( sizeof(u)==sizeof(r) );
+  memcpy(&u, &r, sizeof(u));
+  return ((u>>52)&0x7ff)==0x7ff;
+}
+
+/*
+** Return TRUE if two doubles differ by 0.001 or less
+*/
+static int sameValue(double a, double b){
+  a -= b;
+  return a>=-0.001 && a<=0.001;
+}
+
+/*
+** The "step" function for percentile(Y,P) is called once for each
+** input row.
+*/
+static void percentStep(sqlite3_context *pCtx, int argc, sqlite3_value **argv){
+  Percentile *p;
+  double rPct;
+  int eType;
+  double y;
+  assert( argc==2 );
+
+  /* Requirement 3:  P must be a number between 0 and 100 */
+  eType = sqlite3_value_numeric_type(argv[1]);
+  rPct = sqlite3_value_double(argv[1]);
+  if( (eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT) ||
+      ((rPct = sqlite3_value_double(argv[1]))<0.0 || rPct>100.0) ){
+    sqlite3_result_error(pCtx, "2nd argument to percentile() is not "
+                         "a number between 0.0 and 100.0", -1);
+    return;
+  }
+
+  /* Allocate the session context. */
+  p = (Percentile*)sqlite3_aggregate_context(pCtx, sizeof(*p));
+  if( p==0 ) return;
+
+  /* Remember the P value.  Throw an error if the P value is different
+  ** from any prior row, per Requirement (2). */
+  if( p->rPct==0.0 ){
+    p->rPct = rPct+1.0;
+  }else if( !sameValue(p->rPct,rPct+1.0) ){
+    sqlite3_result_error(pCtx, "2nd argument to percentile() is not the "
+                               "same for all input rows", -1);
+    return;
+  }
+
+  /* Ignore rows for which Y is NULL */
+  eType = sqlite3_value_type(argv[0]);
+  if( eType==SQLITE_NULL ) return;
+
+  /* If not NULL, then Y must be numeric.  Otherwise throw an error.
+  ** Requirement 4 */
+  if( eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT ){
+    sqlite3_result_error(pCtx, "1st argument to percentile() is not "
+                               "numeric", -1);
+    return;
+  }
+
+  /* Throw an error if the Y value is infinity or NaN */
+  y = sqlite3_value_double(argv[0]);
+  if( isInfinity(y) ){
+    sqlite3_result_error(pCtx, "Inf input to percentile()", -1);
+    return;
+  }
+
+  /* Allocate and store the Y */
+  if( p->nUsed>=p->nAlloc ){
+    unsigned n = p->nAlloc*2 + 250;
+    double *a = sqlite3_realloc(p->a, sizeof(double)*n);
+    if( a==0 ){
+      sqlite3_free(p->a);
+      memset(p, 0, sizeof(*p));
+      sqlite3_result_error_nomem(pCtx);
+      return;
+    }
+    p->nAlloc = n;
+    p->a = a;
+  }
+  p->a[p->nUsed++] = y;
+}
+
+/*
+** Compare to doubles for sorting using qsort()
+*/
+static int doubleCmp(const void *pA, const void *pB){
+  double a = *(double*)pA;
+  double b = *(double*)pB;
+  if( a==b ) return 0;
+  if( a<b ) return -1;
+  return +1;
+}
+
+/*
+** Called to compute the final output of percentile() and to clean
+** up all allocated memory.
+*/
+static void percentFinal(sqlite3_context *pCtx){
+  Percentile *p;
+  unsigned i1, i2;
+  double v1, v2;
+  double ix, vx;
+  p = (Percentile*)sqlite3_aggregate_context(pCtx, 0);
+  if( p==0 ) return;
+  if( p->a==0 ) return;
+  if( p->nUsed ){
+    qsort(p->a, p->nUsed, sizeof(double), doubleCmp);
+    ix = (p->rPct-1.0)*(p->nUsed-1)*0.01;
+    i1 = (unsigned)ix;
+    i2 = ix==(double)i1 || i1==p->nUsed-1 ? i1 : i1+1;
+    v1 = p->a[i1];
+    v2 = p->a[i2];
+    vx = v1 + (v2-v1)*(ix-i1);
+    sqlite3_result_double(pCtx, vx);
+  }
+  sqlite3_free(p->a);
+  memset(p, 0, sizeof(*p));
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_percentile_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "percentile", 2, SQLITE_UTF8, 0,
+                               0, percentStep, percentFinal);
+  return rc;
+}
diff --git a/ext/misc/regexp.c b/ext/misc/regexp.c
index 16fa7d0..7244d52 100644
--- a/ext/misc/regexp.c
+++ b/ext/misc/regexp.c
@@ -713,6 +713,7 @@ static void re_sql_func(
   const char *zPattern;     /* The regular expression */
   const unsigned char *zStr;/* String being searched */
   const char *zErr;         /* Compile error message */
+  int setAux = 0;           /* True to invoke sqlite3_set_auxdata() */
 
   pRe = sqlite3_get_auxdata(context, 0);
   if( pRe==0 ){
@@ -728,12 +729,15 @@ static void re_sql_func(
       sqlite3_result_error_nomem(context);
       return;
     }
-    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
+    setAux = 1;
   }
   zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
   if( zStr!=0 ){
     sqlite3_result_int(context, re_match(pRe, zStr, -1));
   }
+  if( setAux ){
+    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
+  }
 }
 
 /*
diff --git a/ext/misc/spellfix.c b/ext/misc/spellfix.c
index eb5442e..2e6743e 100644
--- a/ext/misc/spellfix.c
+++ b/ext/misc/spellfix.c
@@ -26,8 +26,8 @@ SQLITE_EXTENSION_INIT1
 # define NEVER(X)   0
   typedef unsigned char u8;
   typedef unsigned short u16;
-# include <ctype.h>
 #endif
+#include <ctype.h>
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
 
@@ -1893,7 +1893,7 @@ static int spellfix1Init(
   char **pzErr
 ){
   spellfix1_vtab *pNew = 0;
-  const char *zModule = argv[0];
+  /* const char *zModule = argv[0]; // not used */
   const char *zDbName = argv[1];
   const char *zTableName = argv[2];
   int nDbName;
@@ -1933,7 +1933,6 @@ static int spellfix1Init(
 #define SPELLFIX_COL_COMMAND        11
     }
     if( rc==SQLITE_OK && isCreate ){
-      sqlite3_uint64 r;
       spellfix1DbExec(&rc, db,
          "CREATE TABLE IF NOT EXISTS \"%w\".\"%w_vocab\"(\n"
          "  id INTEGER PRIMARY KEY,\n"
@@ -1945,11 +1944,10 @@ static int spellfix1Init(
          ");\n",
          zDbName, zTableName
       );
-      sqlite3_randomness(sizeof(r), &r);
       spellfix1DbExec(&rc, db,
-         "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_index_%llx\" "
+         "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_vocab_index_langid_k2\" "
             "ON \"%w_vocab\"(langid,k2);",
-         zDbName, zModule, r, zTableName
+         zDbName, zTableName, zTableName
       );
     }
     for(i=3; rc==SQLITE_OK && i<argc; i++){
@@ -2051,6 +2049,7 @@ static int spellfix1Close(sqlite3_vtab_cursor *cur){
 **   (D)    scope = $scope
 **   (E)    distance < $distance
 **   (F)    distance <= $distance
+**   (G)    rowid = $rowid
 **
 ** The plan number is a bit mask formed with these bits:
 **
@@ -2060,8 +2059,9 @@ static int spellfix1Close(sqlite3_vtab_cursor *cur){
 **   0x08   (D) is found
 **   0x10   (E) is found
 **   0x20   (F) is found
+**   0x40   (G) is found
 **
-** filter.argv[*] values contains $str, $langid, $top, and $scope,
+** filter.argv[*] values contains $str, $langid, $top, $scope and $rowid
 ** if specified and in that order.
 */
 static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
@@ -2070,6 +2070,7 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   int iTopTerm = -1;
   int iScopeTerm = -1;
   int iDistTerm = -1;
+  int iRowidTerm = -1;
   int i;
   const struct sqlite3_index_constraint *pConstraint;
   pConstraint = pIdxInfo->aConstraint;
@@ -2122,6 +2123,15 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32;
       iDistTerm = i;
     }
+
+    /* Terms of the form:  distance < $dist or distance <= $dist */
+    if( (iPlan & 64)==0
+     && pConstraint->iColumn<0
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ
+    ){
+      iPlan |= 64;
+      iRowidTerm = i;
+    }
   }
   if( iPlan&1 ){
     int idx = 2;
@@ -2148,10 +2158,15 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++;
       pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
     }
-    pIdxInfo->estimatedCost = (double)10000;
+    pIdxInfo->estimatedCost = 1e5;
+  }else if( (iPlan & 64) ){
+    pIdxInfo->idxNum = 64;
+    pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
+    pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
+    pIdxInfo->estimatedCost = 5;
   }else{
     pIdxInfo->idxNum = 0;
-    pIdxInfo->estimatedCost = (double)10000000;
+    pIdxInfo->estimatedCost = 1e50;
   }
   return SQLITE_OK;
 }
@@ -2465,16 +2480,23 @@ static int spellfix1FilterForFullScan(
   int argc,
   sqlite3_value **argv
 ){
-  int rc;
+  int rc = SQLITE_OK;
   char *zSql;
   spellfix1_vtab *pVTab = pCur->pVTab;
   spellfix1ResetCursor(pCur);
+  assert( idxNum==0 || idxNum==64 );
   zSql = sqlite3_mprintf(
-     "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"",
-     pVTab->zDbName, pVTab->zTableName);
+     "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"%s",
+     pVTab->zDbName, pVTab->zTableName,
+     ((idxNum & 64) ? " WHERE rowid=?" : "")
+  );
   if( zSql==0 ) return SQLITE_NOMEM;
   rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0);
   sqlite3_free(zSql);
+  if( rc==SQLITE_OK && (idxNum & 64) ){
+    assert( argc==1 );
+    rc = sqlite3_bind_value(pCur->pFullScan, 1, argv[0]);
+  }
   pCur->nRow = pCur->iRow = 0;
   if( rc==SQLITE_OK ){
     rc = sqlite3_step(pCur->pFullScan);
@@ -2672,7 +2694,7 @@ static int spellfix1Update(
       const char *zCmd = 
          (const char*)sqlite3_value_text(argv[SPELLFIX_COL_COMMAND+2]);
       if( zCmd==0 ){
-        pVTab->zErrMsg = sqlite3_mprintf("%s.word may not be NULL",
+        pVTab->zErrMsg = sqlite3_mprintf("NOT NULL constraint failed: %s.word",
                                          p->zTableName);
         return SQLITE_CONSTRAINT_NOTNULL;
       }
diff --git a/ext/misc/totype.c b/ext/misc/totype.c
new file mode 100644
index 0000000..5dc99f3
--- /dev/null
+++ b/ext/misc/totype.c
@@ -0,0 +1,512 @@
+/*
+** 2013-10-14
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This SQLite extension implements functions tointeger(X) and toreal(X).
+**
+** If X is an integer, real, or string value that can be
+** losslessly represented as an integer, then tointeger(X)
+** returns the corresponding integer value.
+** If X is an 8-byte BLOB then that blob is interpreted as
+** a signed two-compliment little-endian encoding of an integer
+** and tointeger(X) returns the corresponding integer value.
+** Otherwise tointeger(X) return NULL.
+**
+** If X is an integer, real, or string value that can be
+** convert into a real number, preserving at least 15 digits
+** of precision, then toreal(X) returns the corresponding real value.
+** If X is an 8-byte BLOB then that blob is interpreted as
+** a 64-bit IEEE754 big-endian floating point value
+** and toreal(X) returns the corresponding real value.
+** Otherwise toreal(X) return NULL.
+**
+** Note that tointeger(X) of an 8-byte BLOB assumes a little-endian
+** encoding whereas toreal(X) of an 8-byte BLOB assumes a big-endian
+** encoding.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+/*
+** Determine if this is running on a big-endian or little-endian
+** processor
+*/
+#if defined(i386) || defined(__i386__) || defined(_M_IX86)\
+                             || defined(__x86_64) || defined(__x86_64__)
+# define TOTYPE_BIGENDIAN    0
+# define TOTYPE_LITTLEENDIAN 1
+#else
+  const int totype_one = 1;
+# define TOTYPE_BIGENDIAN    (*(char *)(&totype_one)==0)
+# define TOTYPE_LITTLEENDIAN (*(char *)(&totype_one)==1)
+#endif
+
+/*
+** Constants for the largest and smallest possible 64-bit signed integers.
+** These macros are designed to work correctly on both 32-bit and 64-bit
+** compilers.
+*/
+#ifndef LARGEST_INT64
+# define LARGEST_INT64   (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
+#endif
+
+#ifndef SMALLEST_INT64
+# define SMALLEST_INT64  (((sqlite3_int64)-1) - LARGEST_INT64)
+#endif
+
+/*
+** Return TRUE if character c is a whitespace character
+*/
+static int totypeIsspace(unsigned char c){
+  return c==' ' || c=='\t' || c=='\n' || c=='\v' || c=='\f' || c=='\r';
+}
+
+/*
+** Return TRUE if character c is a digit
+*/
+static int totypeIsdigit(unsigned char c){
+  return c>='0' && c<='9';
+}
+
+/*
+** Compare the 19-character string zNum against the text representation
+** value 2^63:  9223372036854775808.  Return negative, zero, or positive
+** if zNum is less than, equal to, or greater than the string.
+** Note that zNum must contain exactly 19 characters.
+**
+** Unlike memcmp() this routine is guaranteed to return the difference
+** in the values of the last digit if the only difference is in the
+** last digit.  So, for example,
+**
+**      totypeCompare2pow63("9223372036854775800")
+**
+** will return -8.
+*/
+static int totypeCompare2pow63(const char *zNum){
+  int c = 0;
+  int i;
+                    /* 012345678901234567 */
+  const char *pow63 = "922337203685477580";
+  for(i=0; c==0 && i<18; i++){
+    c = (zNum[i]-pow63[i])*10;
+  }
+  if( c==0 ){
+    c = zNum[18] - '8';
+  }
+  return c;
+}
+
+/*
+** Convert zNum to a 64-bit signed integer.
+**
+** If the zNum value is representable as a 64-bit twos-complement
+** integer, then write that value into *pNum and return 0.
+**
+** If zNum is exactly 9223372036854665808, return 2.  This special
+** case is broken out because while 9223372036854665808 cannot be a
+** signed 64-bit integer, its negative -9223372036854665808 can be.
+**
+** If zNum is too big for a 64-bit integer and is not
+** 9223372036854665808  or if zNum contains any non-numeric text,
+** then return 1.
+**
+** The string is not necessarily zero-terminated.
+*/
+static int totypeAtoi64(const char *zNum, sqlite3_int64 *pNum, int length){
+  sqlite3_uint64 u = 0;
+  int neg = 0; /* assume positive */
+  int i;
+  int c = 0;
+  int nonNum = 0;
+  const char *zStart;
+  const char *zEnd = zNum + length;
+
+  while( zNum<zEnd && totypeIsspace(*zNum) ) zNum++;
+  if( zNum<zEnd ){
+    if( *zNum=='-' ){
+      neg = 1;
+      zNum++;
+    }else if( *zNum=='+' ){
+      zNum++;
+    }
+  }
+  zStart = zNum;
+  while( zNum<zEnd && zNum[0]=='0' ){ zNum++; } /* Skip leading zeros. */
+  for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i++){
+    u = u*10 + c - '0';
+  }
+  if( u>LARGEST_INT64 ){
+    *pNum = SMALLEST_INT64;
+  }else if( neg ){
+    *pNum = -(sqlite3_int64)u;
+  }else{
+    *pNum = (sqlite3_int64)u;
+  }
+  if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19 || nonNum ){
+    /* zNum is empty or contains non-numeric text or is longer
+    ** than 19 digits (thus guaranteeing that it is too large) */
+    return 1;
+  }else if( i<19 ){
+    /* Less than 19 digits, so we know that it fits in 64 bits */
+    assert( u<=LARGEST_INT64 );
+    return 0;
+  }else{
+    /* zNum is a 19-digit numbers.  Compare it against 9223372036854775808. */
+    c = totypeCompare2pow63(zNum);
+    if( c<0 ){
+      /* zNum is less than 9223372036854775808 so it fits */
+      assert( u<=LARGEST_INT64 );
+      return 0;
+    }else if( c>0 ){
+      /* zNum is greater than 9223372036854775808 so it overflows */
+      return 1;
+    }else{
+      /* zNum is exactly 9223372036854775808.  Fits if negative.  The
+      ** special case 2 overflow if positive */
+      assert( u-1==LARGEST_INT64 );
+      assert( (*pNum)==SMALLEST_INT64 );
+      return neg ? 0 : 2;
+    }
+  }
+}
+
+/*
+** The string z[] is an text representation of a real number.
+** Convert this string to a double and write it into *pResult.
+**
+** The string is not necessarily zero-terminated.
+**
+** Return TRUE if the result is a valid real number (or integer) and FALSE
+** if the string is empty or contains extraneous text.  Valid numbers
+** are in one of these formats:
+**
+**    [+-]digits[E[+-]digits]
+**    [+-]digits.[digits][E[+-]digits]
+**    [+-].digits[E[+-]digits]
+**
+** Leading and trailing whitespace is ignored for the purpose of determining
+** validity.
+**
+** If some prefix of the input string is a valid number, this routine
+** returns FALSE but it still converts the prefix and writes the result
+** into *pResult.
+*/
+static int totypeAtoF(const char *z, double *pResult, int length){
+  const char *zEnd = z + length;
+  /* sign * significand * (10 ^ (esign * exponent)) */
+  int sign = 1;    /* sign of significand */
+  sqlite3_int64 s = 0;       /* significand */
+  int d = 0;       /* adjust exponent for shifting decimal point */
+  int esign = 1;   /* sign of exponent */
+  int e = 0;       /* exponent */
+  int eValid = 1;  /* True exponent is either not used or is well-formed */
+  double result;
+  int nDigits = 0;
+  int nonNum = 0;
+
+  *pResult = 0.0;   /* Default return value, in case of an error */
+
+  /* skip leading spaces */
+  while( z<zEnd && totypeIsspace(*z) ) z++;
+  if( z>=zEnd ) return 0;
+
+  /* get sign of significand */
+  if( *z=='-' ){
+    sign = -1;
+    z++;
+  }else if( *z=='+' ){
+    z++;
+  }
+
+  /* skip leading zeroes */
+  while( z<zEnd && z[0]=='0' ) z++, nDigits++;
+
+  /* copy max significant digits to significand */
+  while( z<zEnd && totypeIsdigit(*z) && s<((LARGEST_INT64-9)/10) ){
+    s = s*10 + (*z - '0');
+    z++, nDigits++;
+  }
+
+  /* skip non-significant significand digits
+  ** (increase exponent by d to shift decimal left) */
+  while( z<zEnd && totypeIsdigit(*z) ) z++, nDigits++, d++;
+  if( z>=zEnd ) goto totype_atof_calc;
+
+  /* if decimal point is present */
+  if( *z=='.' ){
+    z++;
+    /* copy digits from after decimal to significand
+    ** (decrease exponent by d to shift decimal right) */
+    while( z<zEnd && totypeIsdigit(*z) && s<((LARGEST_INT64-9)/10) ){
+      s = s*10 + (*z - '0');
+      z++, nDigits++, d--;
+    }
+    /* skip non-significant digits */
+    while( z<zEnd && totypeIsdigit(*z) ) z++, nDigits++;
+  }
+  if( z>=zEnd ) goto totype_atof_calc;
+
+  /* if exponent is present */
+  if( *z=='e' || *z=='E' ){
+    z++;
+    eValid = 0;
+    if( z>=zEnd ) goto totype_atof_calc;
+    /* get sign of exponent */
+    if( *z=='-' ){
+      esign = -1;
+      z++;
+    }else if( *z=='+' ){
+      z++;
+    }
+    /* copy digits to exponent */
+    while( z<zEnd && totypeIsdigit(*z) ){
+      e = e<10000 ? (e*10 + (*z - '0')) : 10000;
+      z++;
+      eValid = 1;
+    }
+  }
+
+  /* skip trailing spaces */
+  if( nDigits && eValid ){
+    while( z<zEnd && totypeIsspace(*z) ) z++;
+  }
+
+totype_atof_calc:
+  /* adjust exponent by d, and update sign */
+  e = (e*esign) + d;
+  if( e<0 ) {
+    esign = -1;
+    e *= -1;
+  } else {
+    esign = 1;
+  }
+
+  /* if 0 significand */
+  if( !s ) {
+    /* In the IEEE 754 standard, zero is signed.
+    ** Add the sign if we've seen at least one digit */
+    result = (sign<0 && nDigits) ? -(double)0 : (double)0;
+  } else {
+    /* attempt to reduce exponent */
+    if( esign>0 ){
+      while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10;
+    }else{
+      while( !(s%10) && e>0 ) e--,s/=10;
+    }
+
+    /* adjust the sign of significand */
+    s = sign<0 ? -s : s;
+
+    /* if exponent, scale significand as appropriate
+    ** and store in result. */
+    if( e ){
+      double scale = 1.0;
+      /* attempt to handle extremely small/large numbers better */
+      if( e>307 && e<342 ){
+        while( e%308 ) { scale *= 1.0e+1; e -= 1; }
+        if( esign<0 ){
+          result = s / scale;
+          result /= 1.0e+308;
+        }else{
+          result = s * scale;
+          result *= 1.0e+308;
+        }
+      }else if( e>=342 ){
+        if( esign<0 ){
+          result = 0.0*s;
+        }else{
+          result = 1e308*1e308*s;  /* Infinity */
+        }
+      }else{
+        /* 1.0e+22 is the largest power of 10 than can be
+        ** represented exactly. */
+        while( e%22 ) { scale *= 1.0e+1; e -= 1; }
+        while( e>0 ) { scale *= 1.0e+22; e -= 22; }
+        if( esign<0 ){
+          result = s / scale;
+        }else{
+          result = s * scale;
+        }
+      }
+    } else {
+      result = (double)s;
+    }
+  }
+
+  /* store the result */
+  *pResult = result;
+
+  /* return true if number and no extra non-whitespace chracters after */
+  return z>=zEnd && nDigits>0 && eValid && nonNum==0;
+}
+
+/*
+** tointeger(X):  If X is any value (integer, double, blob, or string) that
+** can be losslessly converted into an integer, then make the conversion and
+** return the result.  Otherwise, return NULL.
+*/
+static void tointegerFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( argc==1 );
+  (void)argc;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_FLOAT: {
+      double rVal = sqlite3_value_double(argv[0]);
+      sqlite3_int64 iVal = (sqlite3_int64)rVal;
+      if( rVal==(double)iVal ){
+        sqlite3_result_int64(context, iVal);
+      }
+      break;
+    }
+    case SQLITE_INTEGER: {
+      sqlite3_result_int64(context, sqlite3_value_int64(argv[0]));
+      break;
+    }
+    case SQLITE_BLOB: {
+      const unsigned char *zBlob = sqlite3_value_blob(argv[0]);
+      if( zBlob ){
+        int nBlob = sqlite3_value_bytes(argv[0]);
+        if( nBlob==sizeof(sqlite3_int64) ){
+          sqlite3_int64 iVal;
+          if( TOTYPE_BIGENDIAN ){
+            int i;
+            unsigned char zBlobRev[sizeof(sqlite3_int64)];
+            for(i=0; i<sizeof(sqlite3_int64); i++){
+              zBlobRev[i] = zBlob[sizeof(sqlite3_int64)-1-i];
+            }
+            memcpy(&iVal, zBlobRev, sizeof(sqlite3_int64));
+          }else{
+            memcpy(&iVal, zBlob, sizeof(sqlite3_int64));
+          }
+          sqlite3_result_int64(context, iVal);
+        }
+      }
+      break;
+    }
+    case SQLITE_TEXT: {
+      const unsigned char *zStr = sqlite3_value_text(argv[0]);
+      if( zStr ){
+        int nStr = sqlite3_value_bytes(argv[0]);
+        if( nStr && !totypeIsspace(zStr[0]) ){
+          sqlite3_int64 iVal;
+          if( !totypeAtoi64((const char*)zStr, &iVal, nStr) ){
+            sqlite3_result_int64(context, iVal);
+          }
+        }
+      }
+      break;
+    }
+    default: {
+      assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
+      break;
+    }
+  }
+}
+
+/*
+** toreal(X): If X is any value (integer, double, blob, or string) that can
+** be losslessly converted into a real number, then do so and return that
+** real number.  Otherwise return NULL.
+*/
+#if defined(_MSC_VER)
+#pragma warning(disable: 4748)
+#pragma optimize("", off)
+#endif
+static void torealFunc(
+  sqlite3_context *context,
+  int argc,
+  sqlite3_value **argv
+){
+  assert( argc==1 );
+  (void)argc;
+  switch( sqlite3_value_type(argv[0]) ){
+    case SQLITE_FLOAT: {
+      sqlite3_result_double(context, sqlite3_value_double(argv[0]));
+      break;
+    }
+    case SQLITE_INTEGER: {
+      sqlite3_int64 iVal = sqlite3_value_int64(argv[0]);
+      double rVal = (double)iVal;
+      if( iVal==(sqlite3_int64)rVal ){
+        sqlite3_result_double(context, rVal);
+      }
+      break;
+    }
+    case SQLITE_BLOB: {
+      const unsigned char *zBlob = sqlite3_value_blob(argv[0]);
+      if( zBlob ){
+        int nBlob = sqlite3_value_bytes(argv[0]);
+        if( nBlob==sizeof(double) ){
+          double rVal;
+          if( TOTYPE_LITTLEENDIAN ){
+            int i;
+            unsigned char zBlobRev[sizeof(double)];
+            for(i=0; i<sizeof(double); i++){
+              zBlobRev[i] = zBlob[sizeof(double)-1-i];
+            }
+            memcpy(&rVal, zBlobRev, sizeof(double));
+          }else{
+            memcpy(&rVal, zBlob, sizeof(double));
+          }
+          sqlite3_result_double(context, rVal);
+        }
+      }
+      break;
+    }
+    case SQLITE_TEXT: {
+      const unsigned char *zStr = sqlite3_value_text(argv[0]);
+      if( zStr ){
+        int nStr = sqlite3_value_bytes(argv[0]);
+        if( nStr && !totypeIsspace(zStr[0]) && !totypeIsspace(zStr[nStr-1]) ){
+          double rVal;
+          if( totypeAtoF((const char*)zStr, &rVal, nStr) ){
+            sqlite3_result_double(context, rVal);
+            return;
+          }
+        }
+      }
+      break;
+    }
+    default: {
+      assert( sqlite3_value_type(argv[0])==SQLITE_NULL );
+      break;
+    }
+  }
+}
+#if defined(_MSC_VER)
+#pragma optimize("", on)
+#pragma warning(default: 4748)
+#endif
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_totype_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "tointeger", 1, SQLITE_UTF8, 0,
+                               tointegerFunc, 0, 0);
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "toreal", 1, SQLITE_UTF8, 0,
+                                 torealFunc, 0, 0);
+  }
+  return rc;
+}
diff --git a/ext/misc/vfslog.c b/ext/misc/vfslog.c
new file mode 100644
index 0000000..b55b06f
--- /dev/null
+++ b/ext/misc/vfslog.c
@@ -0,0 +1,759 @@
+/*
+** 2013-10-09
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains the implementation of an SQLite vfs wrapper for
+** unix that generates per-database log files of all disk activity.
+*/
+
+/*
+** This module contains code for a wrapper VFS that causes a log of
+** most VFS calls to be written into a file on disk.
+**
+** Each database connection creates a separate log file in the same
+** directory as the original database and named after the original
+** database.  A unique suffix is added to avoid name collisions.  
+** Separate log files are used so that concurrent processes do not
+** try to write log operations to the same file at the same instant, 
+** resulting in overwritten or comingled log text.
+**
+** Each individual log file records operations by a single database
+** connection on both the original database and its associated rollback
+** journal.
+**
+** The log files are in the comma-separated-value (CSV) format.  The
+** log files can be imported into an SQLite database using the ".import"
+** command of the SQLite command-line shell for analysis.
+**
+** One technique for using this module is to append the text of this
+** module to the end of a standard "sqlite3.c" amalgamation file then
+** add the following compile-time options:
+**
+**     -DSQLITE_EXTRA_INIT=sqlite3_register_vfslog
+**     -DSQLITE_USE_FCNTL_TRACE
+**
+** The first compile-time option causes the sqlite3_register_vfslog()
+** function, defined below, to be invoked when SQLite is initialized.
+** That causes this custom VFS to become the default VFS for all
+** subsequent connections.  The SQLITE_USE_FCNTL_TRACE option causes
+** the SQLite core to issue extra sqlite3_file_control() operations
+** with SQLITE_FCNTL_TRACE to give some indication of what is going
+** on in the core.
+*/
+
+#include "sqlite3.h"
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#if SQLITE_OS_UNIX
+# include <unistd.h>
+#endif
+
+/*
+** Forward declaration of objects used by this utility
+*/
+typedef struct VLogLog VLogLog;
+typedef struct VLogVfs VLogVfs;
+typedef struct VLogFile VLogFile;
+
+/* There is a pair (an array of size 2) of the following objects for
+** each database file being logged.  The first contains the filename
+** and is used to log I/O with the main database.  The second has
+** a NULL filename and is used to log I/O for the journal.  Both
+** out pointers are the same.
+*/
+struct VLogLog {
+  VLogLog *pNext;                 /* Next in a list of all active logs */
+  VLogLog **ppPrev;               /* Pointer to this in the list */
+  int nRef;                       /* Number of references to this object */
+  int nFilename;                  /* Length of zFilename in bytes */
+  char *zFilename;                /* Name of database file.  NULL for journal */
+  FILE *out;                      /* Write information here */
+};
+
+struct VLogVfs {
+  sqlite3_vfs base;               /* VFS methods */
+  sqlite3_vfs *pVfs;              /* Parent VFS */
+};
+
+struct VLogFile {
+  sqlite3_file base;              /* IO methods */
+  sqlite3_file *pReal;            /* Underlying file handle */
+  VLogLog *pLog;                  /* The log file for this file */
+};
+
+#define REALVFS(p) (((VLogVfs*)(p))->pVfs)
+
+/*
+** Methods for VLogFile
+*/
+static int vlogClose(sqlite3_file*);
+static int vlogRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
+static int vlogWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
+static int vlogTruncate(sqlite3_file*, sqlite3_int64 size);
+static int vlogSync(sqlite3_file*, int flags);
+static int vlogFileSize(sqlite3_file*, sqlite3_int64 *pSize);
+static int vlogLock(sqlite3_file*, int);
+static int vlogUnlock(sqlite3_file*, int);
+static int vlogCheckReservedLock(sqlite3_file*, int *pResOut);
+static int vlogFileControl(sqlite3_file*, int op, void *pArg);
+static int vlogSectorSize(sqlite3_file*);
+static int vlogDeviceCharacteristics(sqlite3_file*);
+
+/*
+** Methods for VLogVfs
+*/
+static int vlogOpen(sqlite3_vfs*, const char *, sqlite3_file*, int , int *);
+static int vlogDelete(sqlite3_vfs*, const char *zName, int syncDir);
+static int vlogAccess(sqlite3_vfs*, const char *zName, int flags, int *);
+static int vlogFullPathname(sqlite3_vfs*, const char *zName, int, char *zOut);
+static void *vlogDlOpen(sqlite3_vfs*, const char *zFilename);
+static void vlogDlError(sqlite3_vfs*, int nByte, char *zErrMsg);
+static void (*vlogDlSym(sqlite3_vfs *pVfs, void *p, const char*zSym))(void);
+static void vlogDlClose(sqlite3_vfs*, void*);
+static int vlogRandomness(sqlite3_vfs*, int nByte, char *zOut);
+static int vlogSleep(sqlite3_vfs*, int microseconds);
+static int vlogCurrentTime(sqlite3_vfs*, double*);
+static int vlogGetLastError(sqlite3_vfs*, int, char *);
+static int vlogCurrentTimeInt64(sqlite3_vfs*, sqlite3_int64*);
+
+static VLogVfs vlog_vfs = {
+  {
+    1,                            /* iVersion */
+    0,                            /* szOsFile (set by register_vlog()) */
+    1024,                         /* mxPathname */
+    0,                            /* pNext */
+    "vfslog",                     /* zName */
+    0,                            /* pAppData */
+    vlogOpen,                     /* xOpen */
+    vlogDelete,                   /* xDelete */
+    vlogAccess,                   /* xAccess */
+    vlogFullPathname,             /* xFullPathname */
+    vlogDlOpen,                   /* xDlOpen */
+    vlogDlError,                  /* xDlError */
+    vlogDlSym,                    /* xDlSym */
+    vlogDlClose,                  /* xDlClose */
+    vlogRandomness,               /* xRandomness */
+    vlogSleep,                    /* xSleep */
+    vlogCurrentTime,              /* xCurrentTime */
+    vlogGetLastError,             /* xGetLastError */
+    vlogCurrentTimeInt64          /* xCurrentTimeInt64 */
+  },
+  0
+};
+
+static sqlite3_io_methods vlog_io_methods = {
+  1,                              /* iVersion */
+  vlogClose,                      /* xClose */
+  vlogRead,                       /* xRead */
+  vlogWrite,                      /* xWrite */
+  vlogTruncate,                   /* xTruncate */
+  vlogSync,                       /* xSync */
+  vlogFileSize,                   /* xFileSize */
+  vlogLock,                       /* xLock */
+  vlogUnlock,                     /* xUnlock */
+  vlogCheckReservedLock,          /* xCheckReservedLock */
+  vlogFileControl,                /* xFileControl */
+  vlogSectorSize,                 /* xSectorSize */
+  vlogDeviceCharacteristics,      /* xDeviceCharacteristics */
+  0,                              /* xShmMap */
+  0,                              /* xShmLock */
+  0,                              /* xShmBarrier */
+  0                               /* xShmUnmap */
+};
+
+#if SQLITE_OS_UNIX && !defined(NO_GETTOD)
+#include <sys/time.h>
+static sqlite3_uint64 vlog_time(){
+  struct timeval sTime;
+  gettimeofday(&sTime, 0);
+  return sTime.tv_usec + (sqlite3_uint64)sTime.tv_sec * 1000000;
+}
+#elif SQLITE_OS_WIN
+#include <windows.h>
+#include <time.h>
+static sqlite3_uint64 vlog_time(){
+  FILETIME ft;
+  sqlite3_uint64 u64time = 0;
+ 
+  GetSystemTimeAsFileTime(&ft);
+
+  u64time |= ft.dwHighDateTime;
+  u64time <<= 32;
+  u64time |= ft.dwLowDateTime;
+
+  /* ft is 100-nanosecond intervals, we want microseconds */
+  return u64time /(sqlite3_uint64)10;
+}
+#else
+static sqlite3_uint64 vlog_time(){
+  return 0;
+}
+#endif
+
+
+/*
+** Write a message to the log file
+*/
+static void vlogLogPrint(
+  VLogLog *pLog,                 /* The log file to write into */
+  sqlite3_int64 tStart,            /* Start time of system call */
+  sqlite3_int64 tElapse,           /* Elapse time of system call */
+  const char *zOp,                 /* Type of system call */
+  sqlite3_int64 iArg1,             /* First argument */
+  sqlite3_int64 iArg2,             /* Second argument */
+  const char *zArg3,               /* Third argument */
+  int iRes                         /* Result */
+){
+  char z1[40], z2[40], z3[2000];
+  if( pLog==0 ) return;
+  if( iArg1>=0 ){
+    sqlite3_snprintf(sizeof(z1), z1, "%lld", iArg1);
+  }else{
+    z1[0] = 0;
+  }
+  if( iArg2>=0 ){
+    sqlite3_snprintf(sizeof(z2), z2, "%lld", iArg2);
+  }else{
+    z2[0] = 0;
+  }
+  if( zArg3 ){
+    sqlite3_snprintf(sizeof(z3), z3, "\"%.*w\"", sizeof(z3)-4, zArg3);
+  }else{
+    z3[0] = 0;
+  }
+  fprintf(pLog->out,"%lld,%lld,%s,%d,%s,%s,%s,%d\n",
+      tStart, tElapse, zOp, pLog->zFilename==0, z1, z2, z3, iRes);
+}
+
+/*
+** List of all active log connections.  Protected by the master mutex.
+*/
+static VLogLog *allLogs = 0;
+
+/*
+** Close a VLogLog object
+*/
+static void vlogLogClose(VLogLog *p){
+  if( p ){
+    sqlite3_mutex *pMutex;
+    p->nRef--;
+    if( p->nRef>0 || p->zFilename==0 ) return;
+    pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
+    sqlite3_mutex_enter(pMutex);
+    *p->ppPrev = p->pNext;
+    if( p->pNext ) p->pNext->ppPrev = p->ppPrev;
+    sqlite3_mutex_leave(pMutex);
+    fclose(p->out);
+    sqlite3_free(p);
+  }
+}
+
+/*
+** Open a VLogLog object on the given file
+*/
+static VLogLog *vlogLogOpen(const char *zFilename){
+  int nName = (int)strlen(zFilename);
+  int isJournal = 0;
+  sqlite3_mutex *pMutex;
+  VLogLog *pLog, *pTemp;
+  sqlite3_int64 tNow = 0;
+  if( nName>4 && strcmp(zFilename+nName-4,"-wal")==0 ){
+    return 0;  /* Do not log wal files */
+  }else
+  if( nName>8 && strcmp(zFilename+nName-8,"-journal")==0 ){
+    nName -= 8;
+    isJournal = 1;
+  }else if( nName>12 
+         && sqlite3_strglob("-mj??????9??", zFilename+nName-12)==0 ){
+    return 0;  /* Do not log master journal files */
+  }
+  pTemp = sqlite3_malloc( sizeof(*pLog)*2 + nName + 60 );
+  if( pTemp==0 ) return 0;
+  pMutex = sqlite3_mutex_alloc(SQLITE_MUTEX_STATIC_MASTER);
+  sqlite3_mutex_enter(pMutex);
+  for(pLog=allLogs; pLog; pLog=pLog->pNext){
+    if( pLog->nFilename==nName && !memcmp(pLog->zFilename, zFilename, nName) ){
+      break;
+    }
+  }
+  if( pLog==0 ){
+    pLog = pTemp;
+    pTemp = 0;
+    memset(pLog, 0, sizeof(*pLog)*2);
+    pLog->zFilename = (char*)&pLog[2];
+    tNow = vlog_time();
+    sqlite3_snprintf(nName+60, pLog->zFilename, "%.*s-debuglog-%lld",
+                     nName, zFilename, tNow);
+    pLog->out = fopen(pLog->zFilename, "a");
+    if( pLog->out==0 ){
+      sqlite3_mutex_leave(pMutex);
+      sqlite3_free(pLog);
+      return 0;
+    }
+    pLog->nFilename = nName;
+    pLog[1].out = pLog[0].out;
+    pLog->ppPrev = &allLogs;
+    if( allLogs ) allLogs->ppPrev = &pLog->pNext;
+    pLog->pNext = allLogs;
+    allLogs = pLog;
+  }
+  sqlite3_mutex_leave(pMutex);
+  if( pTemp ){
+    sqlite3_free(pTemp);
+  }else{
+#if SQLITE_OS_UNIX
+    char zHost[200];
+    zHost[0] = 0;
+    gethostname(zHost, sizeof(zHost)-1);
+    zHost[sizeof(zHost)-1] = 0;
+    vlogLogPrint(pLog, tNow, 0, "IDENT", getpid(), -1, zHost, 0);
+#endif
+  }
+  if( pLog && isJournal ) pLog++;
+  pLog->nRef++;
+  return pLog;
+}
+
+
+/*
+** Close an vlog-file.
+*/
+static int vlogClose(sqlite3_file *pFile){
+  sqlite3_uint64 tStart, tElapse;
+  int rc = SQLITE_OK;
+  VLogFile *p = (VLogFile *)pFile;
+
+  tStart = vlog_time();
+  if( p->pReal->pMethods ){
+    rc = p->pReal->pMethods->xClose(p->pReal);
+  }
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "CLOSE", -1, -1, 0, rc);
+  vlogLogClose(p->pLog);
+  return rc;
+}
+
+/*
+** Compute signature for a block of content.
+**
+** For blocks of 16 or fewer bytes, the signature is just a hex dump of
+** the entire block.
+**
+** For blocks of more than 16 bytes, the signature is a hex dump of the
+** first 8 bytes followed by a 64-bit has of the entire block.
+*/
+static void vlogSignature(unsigned char *p, int n, char *zCksum){
+  unsigned int s0 = 0, s1 = 0;
+  unsigned int *pI;
+  int i;
+  if( n<=16 ){
+    for(i=0; i<n; i++) sqlite3_snprintf(3, zCksum+i*2, "%02x", p[i]);
+  }else{ 
+    pI = (unsigned int*)p;
+    for(i=0; i<n-7; i+=8){
+      s0 += pI[0] + s1;
+      s1 += pI[1] + s0;
+      pI += 2;
+    }
+    for(i=0; i<8; i++) sqlite3_snprintf(3, zCksum+i*2, "%02x", p[i]);
+    sqlite3_snprintf(18, zCksum+i*2, "-%08x%08x", s0, s1);
+  }
+}
+
+/*
+** Convert a big-endian 32-bit integer into a native integer
+*/
+static int bigToNative(const unsigned char *x){
+  return (x[0]<<24) + (x[1]<<16) + (x[2]<<8) + x[3];
+}
+
+/*
+** Read data from an vlog-file.
+*/
+static int vlogRead(
+  sqlite3_file *pFile, 
+  void *zBuf, 
+  int iAmt, 
+  sqlite_int64 iOfst
+){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  char zSig[40];
+
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
+  tElapse = vlog_time() - tStart;
+  if( rc==SQLITE_OK ){
+    vlogSignature(zBuf, iAmt, zSig);
+  }else{
+    zSig[0] = 0;
+  }
+  vlogLogPrint(p->pLog, tStart, tElapse, "READ", iAmt, iOfst, zSig, rc);
+  if( rc==SQLITE_OK
+   && p->pLog
+   && p->pLog->zFilename
+   && iOfst<=24
+   && iOfst+iAmt>=28
+  ){
+    unsigned char *x = ((unsigned char*)zBuf)+(24-iOfst);
+    unsigned iCtr, nFree = -1;
+    char *zFree = 0;
+    char zStr[12];
+    iCtr = bigToNative(x);
+    if( iOfst+iAmt>=40 ){
+      zFree = zStr;
+      sqlite3_snprintf(sizeof(zStr), zStr, "%d", bigToNative(x+8));
+      nFree = bigToNative(x+12);
+    }
+    vlogLogPrint(p->pLog, tStart, 0, "CHNGCTR-READ", iCtr, nFree, zFree, 0);
+  }
+  return rc;
+}
+
+/*
+** Write data to an vlog-file.
+*/
+static int vlogWrite(
+  sqlite3_file *pFile,
+  const void *z,
+  int iAmt,
+  sqlite_int64 iOfst
+){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  char zSig[40];
+
+  tStart = vlog_time();
+  vlogSignature((unsigned char*)z, iAmt, zSig);
+  rc = p->pReal->pMethods->xWrite(p->pReal, z, iAmt, iOfst);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "WRITE", iAmt, iOfst, zSig, rc);
+  if( rc==SQLITE_OK
+   && p->pLog
+   && p->pLog->zFilename
+   && iOfst<=24
+   && iOfst+iAmt>=28
+  ){
+    unsigned char *x = ((unsigned char*)z)+(24-iOfst);
+    unsigned iCtr, nFree = -1;
+    char *zFree = 0;
+    char zStr[12];
+    iCtr = bigToNative(x);
+    if( iOfst+iAmt>=40 ){
+      zFree = zStr;
+      sqlite3_snprintf(sizeof(zStr), zStr, "%d", bigToNative(x+8));
+      nFree = bigToNative(x+12);
+    }
+    vlogLogPrint(p->pLog, tStart, 0, "CHNGCTR-WRITE", iCtr, nFree, zFree, 0);
+  }
+  return rc;
+}
+
+/*
+** Truncate an vlog-file.
+*/
+static int vlogTruncate(sqlite3_file *pFile, sqlite_int64 size){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xTruncate(p->pReal, size);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "TRUNCATE", size, -1, 0, rc);
+  return rc;
+}
+
+/*
+** Sync an vlog-file.
+*/
+static int vlogSync(sqlite3_file *pFile, int flags){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xSync(p->pReal, flags);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "SYNC", flags, -1, 0, rc);
+  return rc;
+}
+
+/*
+** Return the current file-size of an vlog-file.
+*/
+static int vlogFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "FILESIZE", *pSize, -1, 0, rc);
+  return rc;
+}
+
+/*
+** Lock an vlog-file.
+*/
+static int vlogLock(sqlite3_file *pFile, int eLock){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xLock(p->pReal, eLock);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "LOCK", eLock, -1, 0, rc);
+  return rc;
+}
+
+/*
+** Unlock an vlog-file.
+*/
+static int vlogUnlock(sqlite3_file *pFile, int eLock){
+  int rc;
+  sqlite3_uint64 tStart;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  vlogLogPrint(p->pLog, tStart, 0, "UNLOCK", eLock, -1, 0, 0);
+  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);
+  return rc;
+}
+
+/*
+** Check if another file-handle holds a RESERVED lock on an vlog-file.
+*/
+static int vlogCheckReservedLock(sqlite3_file *pFile, int *pResOut){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "CHECKRESERVEDLOCK",
+                 *pResOut, -1, "", rc);
+  return rc;
+}
+
+/*
+** File control method. For custom operations on an vlog-file.
+*/
+static int vlogFileControl(sqlite3_file *pFile, int op, void *pArg){
+  VLogFile *p = (VLogFile *)pFile;
+  sqlite3_uint64 tStart, tElapse;
+  int rc;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
+  if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
+    *(char**)pArg = sqlite3_mprintf("vlog/%z", *(char**)pArg);
+  }
+  tElapse = vlog_time() - tStart;
+  if( op==SQLITE_FCNTL_TRACE ){
+    vlogLogPrint(p->pLog, tStart, tElapse, "TRACE", op, -1, pArg, rc);
+  }else if( op==SQLITE_FCNTL_PRAGMA ){
+    const char **azArg = (const char **)pArg;
+    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, -1, azArg[1], rc);
+  }else if( op==SQLITE_FCNTL_SIZE_HINT ){
+    sqlite3_int64 sz = *(sqlite3_int64*)pArg;
+    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, sz, 0, rc);
+  }else{
+    vlogLogPrint(p->pLog, tStart, tElapse, "FILECONTROL", op, -1, 0, rc);
+  }
+  return rc;
+}
+
+/*
+** Return the sector-size in bytes for an vlog-file.
+*/
+static int vlogSectorSize(sqlite3_file *pFile){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xSectorSize(p->pReal);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "SECTORSIZE", -1, -1, 0, rc);
+  return rc;
+}
+
+/*
+** Return the device characteristic flags supported by an vlog-file.
+*/
+static int vlogDeviceCharacteristics(sqlite3_file *pFile){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogFile *p = (VLogFile *)pFile;
+  tStart = vlog_time();
+  rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
+  tElapse = vlog_time() - tStart;
+  vlogLogPrint(p->pLog, tStart, tElapse, "DEVCHAR", -1, -1, 0, rc);
+  return rc;
+}
+
+
+/*
+** Open an vlog file handle.
+*/
+static int vlogOpen(
+  sqlite3_vfs *pVfs,
+  const char *zName,
+  sqlite3_file *pFile,
+  int flags,
+  int *pOutFlags
+){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  sqlite3_int64 iArg2;
+  VLogFile *p = (VLogFile*)pFile;
+
+  p->pReal = (sqlite3_file*)&p[1];
+  if( (flags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_MAIN_JOURNAL))!=0 ){
+    p->pLog = vlogLogOpen(zName);
+  }else{
+    p->pLog = 0;
+  }
+  tStart = vlog_time();
+  rc = REALVFS(pVfs)->xOpen(REALVFS(pVfs), zName, p->pReal, flags, pOutFlags);
+  tElapse = vlog_time() - tStart;
+  iArg2 = pOutFlags ? *pOutFlags : -1;
+  vlogLogPrint(p->pLog, tStart, tElapse, "OPEN", flags, iArg2, 0, rc);
+  if( rc==SQLITE_OK ){
+    pFile->pMethods = &vlog_io_methods;
+  }else{
+    if( p->pLog ) vlogLogClose(p->pLog);
+    p->pLog = 0;
+  }
+  return rc;
+}
+
+/*
+** Delete the file located at zPath. If the dirSync argument is true,
+** ensure the file-system modifications are synced to disk before
+** returning.
+*/
+static int vlogDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogLog *pLog;
+  tStart = vlog_time();
+  rc = REALVFS(pVfs)->xDelete(REALVFS(pVfs), zPath, dirSync);
+  tElapse = vlog_time() - tStart;
+  pLog = vlogLogOpen(zPath);
+  vlogLogPrint(pLog, tStart, tElapse, "DELETE", dirSync, -1, 0, rc);
+  vlogLogClose(pLog);
+  return rc;
+}
+
+/*
+** Test for access permissions. Return true if the requested permission
+** is available, or false otherwise.
+*/
+static int vlogAccess(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int flags, 
+  int *pResOut
+){
+  int rc;
+  sqlite3_uint64 tStart, tElapse;
+  VLogLog *pLog;
+  tStart = vlog_time();
+  rc = REALVFS(pVfs)->xAccess(REALVFS(pVfs), zPath, flags, pResOut);
+  tElapse = vlog_time() - tStart;
+  pLog = vlogLogOpen(zPath);
+  vlogLogPrint(pLog, tStart, tElapse, "ACCESS", flags, *pResOut, 0, rc);
+  vlogLogClose(pLog);
+  return rc;
+}
+
+/*
+** Populate buffer zOut with the full canonical pathname corresponding
+** to the pathname in zPath. zOut is guaranteed to point to a buffer
+** of at least (INST_MAX_PATHNAME+1) bytes.
+*/
+static int vlogFullPathname(
+  sqlite3_vfs *pVfs, 
+  const char *zPath, 
+  int nOut, 
+  char *zOut
+){
+  return REALVFS(pVfs)->xFullPathname(REALVFS(pVfs), zPath, nOut, zOut);
+}
+
+/*
+** Open the dynamic library located at zPath and return a handle.
+*/
+static void *vlogDlOpen(sqlite3_vfs *pVfs, const char *zPath){
+  return REALVFS(pVfs)->xDlOpen(REALVFS(pVfs), zPath);
+}
+
+/*
+** Populate the buffer zErrMsg (size nByte bytes) with a human readable
+** utf-8 string describing the most recent error encountered associated 
+** with dynamic libraries.
+*/
+static void vlogDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
+  REALVFS(pVfs)->xDlError(REALVFS(pVfs), nByte, zErrMsg);
+}
+
+/*
+** Return a pointer to the symbol zSymbol in the dynamic library pHandle.
+*/
+static void (*vlogDlSym(sqlite3_vfs *pVfs, void *p, const char *zSym))(void){
+  return REALVFS(pVfs)->xDlSym(REALVFS(pVfs), p, zSym);
+}
+
+/*
+** Close the dynamic library handle pHandle.
+*/
+static void vlogDlClose(sqlite3_vfs *pVfs, void *pHandle){
+  REALVFS(pVfs)->xDlClose(REALVFS(pVfs), pHandle);
+}
+
+/*
+** Populate the buffer pointed to by zBufOut with nByte bytes of 
+** random data.
+*/
+static int vlogRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
+  return REALVFS(pVfs)->xRandomness(REALVFS(pVfs), nByte, zBufOut);
+}
+
+/*
+** Sleep for nMicro microseconds. Return the number of microseconds 
+** actually slept.
+*/
+static int vlogSleep(sqlite3_vfs *pVfs, int nMicro){
+  return REALVFS(pVfs)->xSleep(REALVFS(pVfs), nMicro);
+}
+
+/*
+** Return the current time as a Julian Day number in *pTimeOut.
+*/
+static int vlogCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
+  return REALVFS(pVfs)->xCurrentTime(REALVFS(pVfs), pTimeOut);
+}
+
+static int vlogGetLastError(sqlite3_vfs *pVfs, int a, char *b){
+  return REALVFS(pVfs)->xGetLastError(REALVFS(pVfs), a, b);
+}
+static int vlogCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *p){
+  return REALVFS(pVfs)->xCurrentTimeInt64(REALVFS(pVfs), p);
+}
+
+/*
+** Register debugvfs as the default VFS for this process.
+*/
+int sqlite3_register_vfslog(const char *zArg){
+  vlog_vfs.pVfs = sqlite3_vfs_find(0);
+  vlog_vfs.base.szOsFile = sizeof(VLogFile) + vlog_vfs.pVfs->szOsFile;
+  return sqlite3_vfs_register(&vlog_vfs.base, 1);
+}
diff --git a/ext/misc/vtshim.c b/ext/misc/vtshim.c
new file mode 100644
index 0000000..01348e8
--- /dev/null
+++ b/ext/misc/vtshim.c
@@ -0,0 +1,551 @@
+/*
+** 2013-06-12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** A shim that sits between the SQLite virtual table interface and
+** runtimes with garbage collector based memory management.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/* Forward references */
+typedef struct vtshim_aux vtshim_aux;
+typedef struct vtshim_vtab vtshim_vtab;
+typedef struct vtshim_cursor vtshim_cursor;
+
+
+/* The vtshim_aux argument is the auxiliary parameter that is passed
+** into sqlite3_create_module_v2().
+*/
+struct vtshim_aux {
+  void *pChildAux;              /* pAux for child virtual tables */
+  void (*xChildDestroy)(void*); /* Destructor for pChildAux */
+  sqlite3_module *pMod;         /* Methods for child virtual tables */
+  sqlite3 *db;                  /* The database to which we are attached */
+  char *zName;                  /* Name of the module */
+  int bDisposed;                /* True if disposed */
+  vtshim_vtab *pAllVtab;        /* List of all vtshim_vtab objects */
+  sqlite3_module sSelf;         /* Methods used by this shim */
+};
+
+/* A vtshim virtual table object */
+struct vtshim_vtab {
+  sqlite3_vtab base;       /* Base class - must be first */
+  sqlite3_vtab *pChild;    /* Child virtual table */
+  vtshim_aux *pAux;        /* Pointer to vtshim_aux object */
+  vtshim_cursor *pAllCur;  /* List of all cursors */
+  vtshim_vtab **ppPrev;    /* Previous on list */
+  vtshim_vtab *pNext;      /* Next on list */
+};
+
+/* A vtshim cursor object */
+struct vtshim_cursor {
+  sqlite3_vtab_cursor base;    /* Base class - must be first */
+  sqlite3_vtab_cursor *pChild; /* Cursor generated by the managed subclass */
+  vtshim_cursor **ppPrev;      /* Previous on list of all cursors */
+  vtshim_cursor *pNext;        /* Next on list of all cursors */
+};
+
+/* Macro used to copy the child vtable error message to outer vtable */
+#define VTSHIM_COPY_ERRMSG()                                             \
+  do {                                                                   \
+    sqlite3_free(pVtab->base.zErrMsg);                                   \
+    pVtab->base.zErrMsg = sqlite3_mprintf("%s", pVtab->pChild->zErrMsg); \
+  } while (0)
+
+/* Methods for the vtshim module */
+static int vtshimCreate(
+  sqlite3 *db,
+  void *ppAux,
+  int argc,
+  const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  vtshim_aux *pAux = (vtshim_aux*)ppAux;
+  vtshim_vtab *pNew;
+  int rc;
+
+  assert( db==pAux->db );
+  if( pAux->bDisposed ){
+    if( pzErr ){
+      *pzErr = sqlite3_mprintf("virtual table was disposed: \"%s\"",
+                               pAux->zName);
+    }
+    return SQLITE_ERROR;
+  }
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  *ppVtab = (sqlite3_vtab*)pNew;
+  if( pNew==0 ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  rc = pAux->pMod->xCreate(db, pAux->pChildAux, argc, argv,
+                           &pNew->pChild, pzErr);
+  if( rc ){
+    sqlite3_free(pNew);
+    *ppVtab = 0;
+  }
+  pNew->pAux = pAux;
+  pNew->ppPrev = &pAux->pAllVtab;
+  pNew->pNext = pAux->pAllVtab;
+  if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext;
+  pAux->pAllVtab = pNew;
+  return rc;
+}
+
+static int vtshimConnect(
+  sqlite3 *db,
+  void *ppAux,
+  int argc,
+  const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  vtshim_aux *pAux = (vtshim_aux*)ppAux;
+  vtshim_vtab *pNew;
+  int rc;
+
+  assert( db==pAux->db );
+  if( pAux->bDisposed ){
+    if( pzErr ){
+      *pzErr = sqlite3_mprintf("virtual table was disposed: \"%s\"",
+                               pAux->zName);
+    }
+    return SQLITE_ERROR;
+  }
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  *ppVtab = (sqlite3_vtab*)pNew;
+  if( pNew==0 ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  rc = pAux->pMod->xConnect(db, pAux->pChildAux, argc, argv,
+                            &pNew->pChild, pzErr);
+  if( rc ){
+    sqlite3_free(pNew);
+    *ppVtab = 0;
+  }
+  pNew->pAux = pAux;
+  pNew->ppPrev = &pAux->pAllVtab;
+  pNew->pNext = pAux->pAllVtab;
+  if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext;
+  pAux->pAllVtab = pNew;
+  return rc;
+}
+
+static int vtshimBestIndex(
+  sqlite3_vtab *pBase,
+  sqlite3_index_info *pIdxInfo
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xBestIndex(pVtab->pChild, pIdxInfo);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimDisconnect(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xDisconnect(pVtab->pChild);
+  }
+  if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev;
+  *pVtab->ppPrev = pVtab->pNext;
+  sqlite3_free(pVtab);
+  return rc;
+}
+
+static int vtshimDestroy(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xDestroy(pVtab->pChild);
+  }
+  if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev;
+  *pVtab->ppPrev = pVtab->pNext;
+  sqlite3_free(pVtab);
+  return rc;
+}
+
+static int vtshimOpen(sqlite3_vtab *pBase, sqlite3_vtab_cursor **ppCursor){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  vtshim_cursor *pCur;
+  int rc;
+  *ppCursor = 0;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  rc = pAux->pMod->xOpen(pVtab->pChild, &pCur->pChild);
+  if( rc ){
+    sqlite3_free(pCur);
+    VTSHIM_COPY_ERRMSG();
+    return rc;
+  }
+  pCur->pChild->pVtab = pVtab->pChild;
+  *ppCursor = &pCur->base;
+  pCur->ppPrev = &pVtab->pAllCur;
+  if( pVtab->pAllCur ) pVtab->pAllCur->ppPrev = &pCur->pNext;
+  pCur->pNext = pVtab->pAllCur;
+  pVtab->pAllCur = pCur;
+  return SQLITE_OK;
+}
+
+static int vtshimClose(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xClose(pCur->pChild);
+    if( rc!=SQLITE_OK ){
+      VTSHIM_COPY_ERRMSG();
+    }
+  }
+  if( pCur->pNext ) pCur->pNext->ppPrev = pCur->ppPrev;
+  *pCur->ppPrev = pCur->pNext;
+  sqlite3_free(pCur);
+  return rc;
+}
+
+static int vtshimFilter(
+  sqlite3_vtab_cursor *pX,
+  int idxNum,
+  const char *idxStr,
+  int argc,
+  sqlite3_value **argv
+){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xFilter(pCur->pChild, idxNum, idxStr, argc, argv);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimNext(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xNext(pCur->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimEof(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return 1;
+  rc = pAux->pMod->xEof(pCur->pChild);
+  VTSHIM_COPY_ERRMSG();
+  return rc;
+}
+
+static int vtshimColumn(sqlite3_vtab_cursor *pX, sqlite3_context *ctx, int i){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xColumn(pCur->pChild, ctx, i);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRowid(sqlite3_vtab_cursor *pX, sqlite3_int64 *pRowid){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRowid(pCur->pChild, pRowid);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimUpdate(
+  sqlite3_vtab *pBase,
+  int argc,
+  sqlite3_value **argv,
+  sqlite3_int64 *pRowid
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xUpdate(pVtab->pChild, argc, argv, pRowid);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimBegin(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xBegin(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimSync(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xSync(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimCommit(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xCommit(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRollback(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRollback(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimFindFunction(
+  sqlite3_vtab *pBase,
+  int nArg,
+  const char *zName,
+  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
+  void **ppArg
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return 0;
+  rc = pAux->pMod->xFindFunction(pVtab->pChild, nArg, zName, pxFunc, ppArg);
+  VTSHIM_COPY_ERRMSG();
+  return rc;
+}
+
+static int vtshimRename(sqlite3_vtab *pBase, const char *zNewName){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRename(pVtab->pChild, zNewName);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimSavepoint(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xSavepoint(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRelease(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRelease(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRollbackTo(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRollbackTo(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+/* The destructor function for a disposible module */
+static void vtshimAuxDestructor(void *pXAux){
+  vtshim_aux *pAux = (vtshim_aux*)pXAux;
+  assert( pAux->pAllVtab==0 );
+  if( !pAux->bDisposed && pAux->xChildDestroy ){
+    pAux->xChildDestroy(pAux->pChildAux);
+    pAux->xChildDestroy = 0;
+  }
+  sqlite3_free(pAux->zName);
+  sqlite3_free(pAux->pMod);
+  sqlite3_free(pAux);
+}
+
+static int vtshimCopyModule(
+  const sqlite3_module *pMod,   /* Source module to be copied */
+  sqlite3_module **ppMod        /* Destination for copied module */
+){
+  sqlite3_module *p;
+  if( !pMod || !ppMod ) return SQLITE_ERROR;
+  p = sqlite3_malloc( sizeof(*p) );
+  if( p==0 ) return SQLITE_NOMEM;
+  memcpy(p, pMod, sizeof(*p));
+  *ppMod = p;
+  return SQLITE_OK;
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+void *sqlite3_create_disposable_module(
+  sqlite3 *db,               /* SQLite connection to register module with */
+  const char *zName,         /* Name of the module */
+  const sqlite3_module *p,   /* Methods for the module */
+  void *pClientData,         /* Client data for xCreate/xConnect */
+  void(*xDestroy)(void*)     /* Module destructor function */
+){
+  vtshim_aux *pAux;
+  sqlite3_module *pMod;
+  int rc;
+  pAux = sqlite3_malloc( sizeof(*pAux) );
+  if( pAux==0 ){
+    if( xDestroy ) xDestroy(pClientData);
+    return 0;
+  }
+  rc = vtshimCopyModule(p, &pMod);
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(pAux);
+    return 0;
+  }
+  pAux->pChildAux = pClientData;
+  pAux->xChildDestroy = xDestroy;
+  pAux->pMod = pMod;
+  pAux->db = db;
+  pAux->zName = sqlite3_mprintf("%s", zName);
+  pAux->bDisposed = 0;
+  pAux->pAllVtab = 0;
+  pAux->sSelf.iVersion = p->iVersion<=2 ? p->iVersion : 2;
+  pAux->sSelf.xCreate = p->xCreate ? vtshimCreate : 0;
+  pAux->sSelf.xConnect = p->xConnect ? vtshimConnect : 0;
+  pAux->sSelf.xBestIndex = p->xBestIndex ? vtshimBestIndex : 0;
+  pAux->sSelf.xDisconnect = p->xDisconnect ? vtshimDisconnect : 0;
+  pAux->sSelf.xDestroy = p->xDestroy ? vtshimDestroy : 0;
+  pAux->sSelf.xOpen = p->xOpen ? vtshimOpen : 0;
+  pAux->sSelf.xClose = p->xClose ? vtshimClose : 0;
+  pAux->sSelf.xFilter = p->xFilter ? vtshimFilter : 0;
+  pAux->sSelf.xNext = p->xNext ? vtshimNext : 0;
+  pAux->sSelf.xEof = p->xEof ? vtshimEof : 0;
+  pAux->sSelf.xColumn = p->xColumn ? vtshimColumn : 0;
+  pAux->sSelf.xRowid = p->xRowid ? vtshimRowid : 0;
+  pAux->sSelf.xUpdate = p->xUpdate ? vtshimUpdate : 0;
+  pAux->sSelf.xBegin = p->xBegin ? vtshimBegin : 0;
+  pAux->sSelf.xSync = p->xSync ? vtshimSync : 0;
+  pAux->sSelf.xCommit = p->xCommit ? vtshimCommit : 0;
+  pAux->sSelf.xRollback = p->xRollback ? vtshimRollback : 0;
+  pAux->sSelf.xFindFunction = p->xFindFunction ? vtshimFindFunction : 0;
+  pAux->sSelf.xRename = p->xRename ? vtshimRename : 0;
+  if( p->iVersion>=2 ){
+    pAux->sSelf.xSavepoint = p->xSavepoint ? vtshimSavepoint : 0;
+    pAux->sSelf.xRelease = p->xRelease ? vtshimRelease : 0;
+    pAux->sSelf.xRollbackTo = p->xRollbackTo ? vtshimRollbackTo : 0;
+  }else{
+    pAux->sSelf.xSavepoint = 0;
+    pAux->sSelf.xRelease = 0;
+    pAux->sSelf.xRollbackTo = 0;
+  }
+  rc = sqlite3_create_module_v2(db, zName, &pAux->sSelf,
+                                pAux, vtshimAuxDestructor);
+  return rc==SQLITE_OK ? (void*)pAux : 0;
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+void sqlite3_dispose_module(void *pX){
+  vtshim_aux *pAux = (vtshim_aux*)pX;
+  if( !pAux->bDisposed ){
+    vtshim_vtab *pVtab;
+    vtshim_cursor *pCur;
+    for(pVtab=pAux->pAllVtab; pVtab; pVtab=pVtab->pNext){
+      for(pCur=pVtab->pAllCur; pCur; pCur=pCur->pNext){
+        pAux->pMod->xClose(pCur->pChild);
+      }
+      pAux->pMod->xDisconnect(pVtab->pChild);
+    }
+    pAux->bDisposed = 1;
+    if( pAux->xChildDestroy ){
+      pAux->xChildDestroy(pAux->pChildAux);
+      pAux->xChildDestroy = 0;
+    }
+  }
+}
+
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_vtshim_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  return SQLITE_OK;
+}
diff --git a/ext/rtree/rtree.c b/ext/rtree/rtree.c
index 16a316f..8150538 100644
--- a/ext/rtree/rtree.c
+++ b/ext/rtree/rtree.c
@@ -54,48 +54,6 @@
 
 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RTREE)
 
-/*
-** This file contains an implementation of a couple of different variants
-** of the r-tree algorithm. See the README file for further details. The 
-** same data-structure is used for all, but the algorithms for insert and
-** delete operations vary. The variants used are selected at compile time 
-** by defining the following symbols:
-*/
-
-/* Either, both or none of the following may be set to activate 
-** r*tree variant algorithms.
-*/
-#define VARIANT_RSTARTREE_CHOOSESUBTREE 0
-#define VARIANT_RSTARTREE_REINSERT      1
-
-/* 
-** Exactly one of the following must be set to 1.
-*/
-#define VARIANT_GUTTMAN_QUADRATIC_SPLIT 0
-#define VARIANT_GUTTMAN_LINEAR_SPLIT    0
-#define VARIANT_RSTARTREE_SPLIT         1
-
-#define VARIANT_GUTTMAN_SPLIT \
-        (VARIANT_GUTTMAN_LINEAR_SPLIT||VARIANT_GUTTMAN_QUADRATIC_SPLIT)
-
-#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
-  #define PickNext QuadraticPickNext
-  #define PickSeeds QuadraticPickSeeds
-  #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_GUTTMAN_LINEAR_SPLIT
-  #define PickNext LinearPickNext
-  #define PickSeeds LinearPickSeeds
-  #define AssignCells splitNodeGuttman
-#endif
-#if VARIANT_RSTARTREE_SPLIT
-  #define AssignCells splitNodeStartree
-#endif
-
-#if !defined(NDEBUG) && !defined(SQLITE_DEBUG) 
-# define NDEBUG 1
-#endif
-
 #ifndef SQLITE_CORE
   #include "sqlite3ext.h"
   SQLITE_EXTENSION_INIT1
@@ -105,11 +63,13 @@
 
 #include <string.h>
 #include <assert.h>
+#include <stdio.h>
 
 #ifndef SQLITE_AMALGAMATION
 #include "sqlite3rtree.h"
 typedef sqlite3_int64 i64;
 typedef unsigned char u8;
+typedef unsigned short u16;
 typedef unsigned int u32;
 #endif
 
@@ -127,6 +87,7 @@ typedef struct RtreeConstraint RtreeConstraint;
 typedef struct RtreeMatchArg RtreeMatchArg;
 typedef struct RtreeGeomCallback RtreeGeomCallback;
 typedef union RtreeCoord RtreeCoord;
+typedef struct RtreeSearchPoint RtreeSearchPoint;
 
 /* The rtree may have between 1 and RTREE_MAX_DIMENSIONS dimensions. */
 #define RTREE_MAX_DIMENSIONS 5
@@ -135,22 +96,33 @@ typedef union RtreeCoord RtreeCoord;
 ** ever contain very many entries, so a fixed number of buckets is 
 ** used.
 */
-#define HASHSIZE 128
+#define HASHSIZE 97
+
+/* The xBestIndex method of this virtual table requires an estimate of
+** the number of rows in the virtual table to calculate the costs of
+** various strategies. If possible, this estimate is loaded from the
+** sqlite_stat1 table (with RTREE_MIN_ROWEST as a hard-coded minimum).
+** Otherwise, if no sqlite_stat1 entry is available, use 
+** RTREE_DEFAULT_ROWEST.
+*/
+#define RTREE_DEFAULT_ROWEST 1048576
+#define RTREE_MIN_ROWEST         100
 
 /* 
 ** An rtree virtual-table object.
 */
 struct Rtree {
-  sqlite3_vtab base;
+  sqlite3_vtab base;          /* Base class.  Must be first */
   sqlite3 *db;                /* Host database connection */
   int iNodeSize;              /* Size in bytes of each node in the node table */
-  int nDim;                   /* Number of dimensions */
-  int nBytesPerCell;          /* Bytes consumed per cell */
+  u8 nDim;                    /* Number of dimensions */
+  u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */
+  u8 nBytesPerCell;           /* Bytes consumed per cell */
   int iDepth;                 /* Current depth of the r-tree structure */
   char *zDb;                  /* Name of database containing r-tree table */
   char *zName;                /* Name of r-tree table */ 
-  RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 
   int nBusy;                  /* Current number of users of this structure */
+  i64 nRowEst;                /* Estimated number of rows in this table */
 
   /* List of nodes removed during a CondenseTree operation. List is
   ** linked together via the pointer normally used for hash chains -
@@ -175,10 +147,10 @@ struct Rtree {
   sqlite3_stmt *pWriteParent;
   sqlite3_stmt *pDeleteParent;
 
-  int eCoordType;
+  RtreeNode *aHash[HASHSIZE]; /* Hash table of in-memory nodes. */ 
 };
 
-/* Possible values for eCoordType: */
+/* Possible values for Rtree.eCoordType: */
 #define RTREE_COORD_REAL32 0
 #define RTREE_COORD_INT32  1
 
@@ -190,12 +162,31 @@ struct Rtree {
 #ifdef SQLITE_RTREE_INT_ONLY
   typedef sqlite3_int64 RtreeDValue;       /* High accuracy coordinate */
   typedef int RtreeValue;                  /* Low accuracy coordinate */
+# define RTREE_ZERO 0
 #else
   typedef double RtreeDValue;              /* High accuracy coordinate */
   typedef float RtreeValue;                /* Low accuracy coordinate */
+# define RTREE_ZERO 0.0
 #endif
 
 /*
+** When doing a search of an r-tree, instances of the following structure
+** record intermediate results from the tree walk.
+**
+** The id is always a node-id.  For iLevel>=1 the id is the node-id of
+** the node that the RtreeSearchPoint represents.  When iLevel==0, however,
+** the id is of the parent node and the cell that RtreeSearchPoint
+** represents is the iCell-th entry in the parent node.
+*/
+struct RtreeSearchPoint {
+  RtreeDValue rScore;    /* The score for this node.  Smallest goes first. */
+  sqlite3_int64 id;      /* Node ID */
+  u8 iLevel;             /* 0=entries.  1=leaf node.  2+ for higher */
+  u8 eWithin;            /* PARTLY_WITHIN or FULLY_WITHIN */
+  u8 iCell;              /* Cell index within the node */
+};
+
+/*
 ** The minimum number of cells allowed for a node is a third of the 
 ** maximum. In Gutman's notation:
 **
@@ -217,21 +208,44 @@ struct Rtree {
 */
 #define RTREE_MAX_DEPTH 40
 
+
+/*
+** Number of entries in the cursor RtreeNode cache.  The first entry is
+** used to cache the RtreeNode for RtreeCursor.sPoint.  The remaining
+** entries cache the RtreeNode for the first elements of the priority queue.
+*/
+#define RTREE_CACHE_SZ  5
+
 /* 
 ** An rtree cursor object.
 */
 struct RtreeCursor {
-  sqlite3_vtab_cursor base;
-  RtreeNode *pNode;                 /* Node cursor is currently pointing at */
-  int iCell;                        /* Index of current cell in pNode */
+  sqlite3_vtab_cursor base;         /* Base class.  Must be first */
+  u8 atEOF;                         /* True if at end of search */
+  u8 bPoint;                        /* True if sPoint is valid */
   int iStrategy;                    /* Copy of idxNum search parameter */
   int nConstraint;                  /* Number of entries in aConstraint */
   RtreeConstraint *aConstraint;     /* Search constraints. */
+  int nPointAlloc;                  /* Number of slots allocated for aPoint[] */
+  int nPoint;                       /* Number of slots used in aPoint[] */
+  int mxLevel;                      /* iLevel value for root of the tree */
+  RtreeSearchPoint *aPoint;         /* Priority queue for search points */
+  RtreeSearchPoint sPoint;          /* Cached next search point */
+  RtreeNode *aNode[RTREE_CACHE_SZ]; /* Rtree node cache */
+  u32 anQueue[RTREE_MAX_DEPTH+1];   /* Number of queued entries by iLevel */
 };
 
+/* Return the Rtree of a RtreeCursor */
+#define RTREE_OF_CURSOR(X)   ((Rtree*)((X)->base.pVtab))
+
+/*
+** A coordinate can be either a floating point number or a integer.  All
+** coordinates within a single R-Tree are always of the same time.
+*/
 union RtreeCoord {
-  RtreeValue f;
-  int i;
+  RtreeValue f;      /* Floating point value */
+  int i;             /* Integer value */
+  u32 u;             /* Unsigned for byte-order conversions */
 };
 
 /*
@@ -256,38 +270,67 @@ union RtreeCoord {
 struct RtreeConstraint {
   int iCoord;                     /* Index of constrained coordinate */
   int op;                         /* Constraining operation */
-  RtreeDValue rValue;             /* Constraint value. */
-  int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
-  sqlite3_rtree_geometry *pGeom;  /* Constraint callback argument for a MATCH */
+  union {
+    RtreeDValue rValue;             /* Constraint value. */
+    int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*);
+    int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  } u;
+  sqlite3_rtree_query_info *pInfo;  /* xGeom and xQueryFunc argument */
 };
 
 /* Possible values for RtreeConstraint.op */
-#define RTREE_EQ    0x41
-#define RTREE_LE    0x42
-#define RTREE_LT    0x43
-#define RTREE_GE    0x44
-#define RTREE_GT    0x45
-#define RTREE_MATCH 0x46
+#define RTREE_EQ    0x41  /* A */
+#define RTREE_LE    0x42  /* B */
+#define RTREE_LT    0x43  /* C */
+#define RTREE_GE    0x44  /* D */
+#define RTREE_GT    0x45  /* E */
+#define RTREE_MATCH 0x46  /* F: Old-style sqlite3_rtree_geometry_callback() */
+#define RTREE_QUERY 0x47  /* G: New-style sqlite3_rtree_query_callback() */
+
 
 /* 
 ** An rtree structure node.
 */
 struct RtreeNode {
-  RtreeNode *pParent;               /* Parent node */
-  i64 iNode;
-  int nRef;
-  int isDirty;
-  u8 *zData;
-  RtreeNode *pNext;                 /* Next node in this hash chain */
+  RtreeNode *pParent;         /* Parent node */
+  i64 iNode;                  /* The node number */
+  int nRef;                   /* Number of references to this node */
+  int isDirty;                /* True if the node needs to be written to disk */
+  u8 *zData;                  /* Content of the node, as should be on disk */
+  RtreeNode *pNext;           /* Next node in this hash collision chain */
 };
+
+/* Return the number of cells in a node  */
 #define NCELL(pNode) readInt16(&(pNode)->zData[2])
 
 /* 
-** Structure to store a deserialized rtree record.
+** A single cell from a node, deserialized
 */
 struct RtreeCell {
-  i64 iRowid;
-  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];
+  i64 iRowid;                                 /* Node or entry ID */
+  RtreeCoord aCoord[RTREE_MAX_DIMENSIONS*2];  /* Bounding box coordinates */
+};
+
+
+/*
+** This object becomes the sqlite3_user_data() for the SQL functions
+** that are created by sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() and which appear on the right of MATCH
+** operators in order to constrain a search.
+**
+** xGeom and xQueryFunc are the callback functions.  Exactly one of 
+** xGeom and xQueryFunc fields is non-NULL, depending on whether the
+** SQL function was created using sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback().
+** 
+** This object is deleted automatically by the destructor mechanism in
+** sqlite3_create_function_v2().
+*/
+struct RtreeGeomCallback {
+  int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
+  int (*xQueryFunc)(sqlite3_rtree_query_info*);
+  void (*xDestructor)(void*);
+  void *pContext;
 };
 
 
@@ -299,29 +342,16 @@ struct RtreeCell {
 #define RTREE_GEOMETRY_MAGIC 0x891245AB
 
 /*
-** An instance of this structure must be supplied as a blob argument to
-** the right-hand-side of an SQL MATCH operator used to constrain an
-** r-tree query.
+** An instance of this structure (in the form of a BLOB) is returned by
+** the SQL functions that sqlite3_rtree_geometry_callback() and
+** sqlite3_rtree_query_callback() create, and is read as the right-hand
+** operand to the MATCH operator of an R-Tree.
 */
 struct RtreeMatchArg {
-  u32 magic;                      /* Always RTREE_GEOMETRY_MAGIC */
-  int (*xGeom)(sqlite3_rtree_geometry *, int, RtreeDValue*, int *);
-  void *pContext;
-  int nParam;
-  RtreeDValue aParam[1];
-};
-
-/*
-** When a geometry callback is created (see sqlite3_rtree_geometry_callback),
-** a single instance of the following structure is allocated. It is used
-** as the context for the user-function created by by s_r_g_c(). The object
-** is eventually deleted by the destructor mechanism provided by
-** sqlite3_create_function_v2() (which is called by s_r_g_c() to create
-** the geometry callback function).
-*/
-struct RtreeGeomCallback {
-  int (*xGeom)(sqlite3_rtree_geometry*, int, RtreeDValue*, int*);
-  void *pContext;
+  u32 magic;                  /* Always RTREE_GEOMETRY_MAGIC */
+  RtreeGeomCallback cb;       /* Info about the callback functions */
+  int nParam;                 /* Number of parameters to the SQL function */
+  RtreeDValue aParam[1];      /* Values for parameters to the SQL function */
 };
 
 #ifndef MAX
@@ -415,10 +445,7 @@ static void nodeZero(Rtree *pRtree, RtreeNode *p){
 ** in the Rtree.aHash table.
 */
 static int nodeHash(i64 iNode){
-  return (
-    (iNode>>56) ^ (iNode>>48) ^ (iNode>>40) ^ (iNode>>32) ^ 
-    (iNode>>24) ^ (iNode>>16) ^ (iNode>> 8) ^ (iNode>> 0)
-  ) % HASHSIZE;
+  return iNode % HASHSIZE;
 }
 
 /*
@@ -478,8 +505,7 @@ static RtreeNode *nodeNew(Rtree *pRtree, RtreeNode *pParent){
 /*
 ** Obtain a reference to an r-tree node.
 */
-static int
-nodeAcquire(
+static int nodeAcquire(
   Rtree *pRtree,             /* R-tree structure */
   i64 iNode,                 /* Node number to load */
   RtreeNode *pParent,        /* Either the parent node or NULL */
@@ -568,10 +594,10 @@ nodeAcquire(
 ** Overwrite cell iCell of node pNode with the contents of pCell.
 */
 static void nodeOverwriteCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode,  
-  RtreeCell *pCell, 
-  int iCell
+  Rtree *pRtree,             /* The overall R-Tree */
+  RtreeNode *pNode,          /* The node into which the cell is to be written */
+  RtreeCell *pCell,          /* The cell to write */
+  int iCell                  /* Index into pNode into which pCell is written */
 ){
   int ii;
   u8 *p = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
@@ -583,7 +609,7 @@ static void nodeOverwriteCell(
 }
 
 /*
-** Remove cell the cell with index iCell from node pNode.
+** Remove the cell with index iCell from node pNode.
 */
 static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){
   u8 *pDst = &pNode->zData[4 + pRtree->nBytesPerCell*iCell];
@@ -600,11 +626,10 @@ static void nodeDeleteCell(Rtree *pRtree, RtreeNode *pNode, int iCell){
 **
 ** If there is not enough free space in pNode, return SQLITE_FULL.
 */
-static int
-nodeInsertCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  RtreeCell *pCell 
+static int nodeInsertCell(
+  Rtree *pRtree,                /* The overall R-Tree */
+  RtreeNode *pNode,             /* Write new cell into this node */
+  RtreeCell *pCell              /* The cell to be inserted */
 ){
   int nCell;                    /* Current number of cells in pNode */
   int nMaxCell;                 /* Maximum number of cells for pNode */
@@ -625,8 +650,7 @@ nodeInsertCell(
 /*
 ** If the node is dirty, write it out to the database.
 */
-static int
-nodeWrite(Rtree *pRtree, RtreeNode *pNode){
+static int nodeWrite(Rtree *pRtree, RtreeNode *pNode){
   int rc = SQLITE_OK;
   if( pNode->isDirty ){
     sqlite3_stmt *p = pRtree->pWriteNode;
@@ -651,8 +675,7 @@ nodeWrite(Rtree *pRtree, RtreeNode *pNode){
 ** Release a reference to a node. If the node is dirty and the reference
 ** count drops to zero, the node data is written to the database.
 */
-static int
-nodeRelease(Rtree *pRtree, RtreeNode *pNode){
+static int nodeRelease(Rtree *pRtree, RtreeNode *pNode){
   int rc = SQLITE_OK;
   if( pNode ){
     assert( pNode->nRef>0 );
@@ -680,9 +703,9 @@ nodeRelease(Rtree *pRtree, RtreeNode *pNode){
 ** an internal node, then the 64-bit integer is a child page number.
 */
 static i64 nodeGetRowid(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell
+  Rtree *pRtree,       /* The overall R-Tree */
+  RtreeNode *pNode,    /* The node from which to extract the ID */
+  int iCell            /* The cell index from which to extract the ID */
 ){
   assert( iCell<NCELL(pNode) );
   return readInt64(&pNode->zData[4 + pRtree->nBytesPerCell*iCell]);
@@ -692,11 +715,11 @@ static i64 nodeGetRowid(
 ** Return coordinate iCoord from cell iCell in node pNode.
 */
 static void nodeGetCoord(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell,
-  int iCoord,
-  RtreeCoord *pCoord           /* Space to write result to */
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node from which to extract a coordinate */
+  int iCell,                   /* The index of the cell within the node */
+  int iCoord,                  /* Which coordinate to extract */
+  RtreeCoord *pCoord           /* OUT: Space to write result to */
 ){
   readCoord(&pNode->zData[12 + pRtree->nBytesPerCell*iCell + 4*iCoord], pCoord);
 }
@@ -706,15 +729,20 @@ static void nodeGetCoord(
 ** to by pCell with the results.
 */
 static void nodeGetCell(
-  Rtree *pRtree, 
-  RtreeNode *pNode, 
-  int iCell,
-  RtreeCell *pCell
+  Rtree *pRtree,               /* The overall R-Tree */
+  RtreeNode *pNode,            /* The node containing the cell to be read */
+  int iCell,                   /* Index of the cell within the node */
+  RtreeCell *pCell             /* OUT: Write the cell contents here */
 ){
-  int ii;
+  u8 *pData;
+  u8 *pEnd;
+  RtreeCoord *pCoord;
   pCell->iRowid = nodeGetRowid(pRtree, pNode, iCell);
-  for(ii=0; ii<pRtree->nDim*2; ii++){
-    nodeGetCoord(pRtree, pNode, iCell, ii, &pCell->aCoord[ii]);
+  pData = pNode->zData + (12 + pRtree->nBytesPerCell*iCell);
+  pEnd = pData + pRtree->nDim*8;
+  pCoord = pCell->aCoord;
+  for(; pData<pEnd; pData+=4, pCoord++){
+    readCoord(pData, pCoord);
   }
 }
 
@@ -840,10 +868,10 @@ static void freeCursorConstraints(RtreeCursor *pCsr){
   if( pCsr->aConstraint ){
     int i;                        /* Used to iterate through constraint array */
     for(i=0; i<pCsr->nConstraint; i++){
-      sqlite3_rtree_geometry *pGeom = pCsr->aConstraint[i].pGeom;
-      if( pGeom ){
-        if( pGeom->xDelUser ) pGeom->xDelUser(pGeom->pUser);
-        sqlite3_free(pGeom);
+      sqlite3_rtree_query_info *pInfo = pCsr->aConstraint[i].pInfo;
+      if( pInfo ){
+        if( pInfo->xDelUser ) pInfo->xDelUser(pInfo->pUser);
+        sqlite3_free(pInfo);
       }
     }
     sqlite3_free(pCsr->aConstraint);
@@ -856,12 +884,13 @@ static void freeCursorConstraints(RtreeCursor *pCsr){
 */
 static int rtreeClose(sqlite3_vtab_cursor *cur){
   Rtree *pRtree = (Rtree *)(cur->pVtab);
-  int rc;
+  int ii;
   RtreeCursor *pCsr = (RtreeCursor *)cur;
   freeCursorConstraints(pCsr);
-  rc = nodeRelease(pRtree, pCsr->pNode);
+  sqlite3_free(pCsr->aPoint);
+  for(ii=0; ii<RTREE_CACHE_SZ; ii++) nodeRelease(pRtree, pCsr->aNode[ii]);
   sqlite3_free(pCsr);
-  return rc;
+  return SQLITE_OK;
 }
 
 /*
@@ -872,194 +901,164 @@ static int rtreeClose(sqlite3_vtab_cursor *cur){
 */
 static int rtreeEof(sqlite3_vtab_cursor *cur){
   RtreeCursor *pCsr = (RtreeCursor *)cur;
-  return (pCsr->pNode==0);
+  return pCsr->atEOF;
 }
 
 /*
-** The r-tree constraint passed as the second argument to this function is
-** guaranteed to be a MATCH constraint.
-*/
-static int testRtreeGeom(
-  Rtree *pRtree,                  /* R-Tree object */
-  RtreeConstraint *pConstraint,   /* MATCH constraint to test */
-  RtreeCell *pCell,               /* Cell to test */
-  int *pbRes                      /* OUT: Test result */
-){
-  int i;
-  RtreeDValue aCoord[RTREE_MAX_DIMENSIONS*2];
-  int nCoord = pRtree->nDim*2;
-
-  assert( pConstraint->op==RTREE_MATCH );
-  assert( pConstraint->pGeom );
-
-  for(i=0; i<nCoord; i++){
-    aCoord[i] = DCOORD(pCell->aCoord[i]);
-  }
-  return pConstraint->xGeom(pConstraint->pGeom, nCoord, aCoord, pbRes);
+** Convert raw bits from the on-disk RTree record into a coordinate value.
+** The on-disk format is big-endian and needs to be converted for little-
+** endian platforms.  The on-disk record stores integer coordinates if
+** eInt is true and it stores 32-bit floating point records if eInt is
+** false.  a[] is the four bytes of the on-disk record to be decoded.
+** Store the results in "r".
+**
+** There are three versions of this macro, one each for little-endian and
+** big-endian processors and a third generic implementation.  The endian-
+** specific implementations are much faster and are preferred if the
+** processor endianness is known at compile-time.  The SQLITE_BYTEORDER
+** macro is part of sqliteInt.h and hence the endian-specific
+** implementation will only be used if this module is compiled as part
+** of the amalgamation.
+*/
+#if defined(SQLITE_BYTEORDER) && SQLITE_BYTEORDER==1234
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    c.u = ((c.u>>24)&0xff)|((c.u>>8)&0xff00)|                   \
+          ((c.u&0xff)<<24)|((c.u&0xff00)<<8);                   \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#elif defined(SQLITE_BYTEORDER) && SQLITE_BYTEORDER==4321
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    memcpy(&c.u,a,4);                                           \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
 }
+#else
+#define RTREE_DECODE_COORD(eInt, a, r) {                        \
+    RtreeCoord c;    /* Coordinate decoded */                   \
+    c.u = ((u32)a[0]<<24) + ((u32)a[1]<<16)                     \
+           +((u32)a[2]<<8) + a[3];                              \
+    r = eInt ? (sqlite3_rtree_dbl)c.i : (sqlite3_rtree_dbl)c.f; \
+}
+#endif
 
-/* 
-** Cursor pCursor currently points to a cell in a non-leaf page.
-** Set *pbEof to true if the sub-tree headed by the cell is filtered
-** (excluded) by the constraints in the pCursor->aConstraint[] 
-** array, or false otherwise.
-**
-** Return SQLITE_OK if successful or an SQLite error code if an error
-** occurs within a geometry callback.
+/*
+** Check the RTree node or entry given by pCellData and p against the MATCH
+** constraint pConstraint.  
 */
-static int testRtreeCell(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
-  RtreeCell cell;
-  int ii;
-  int bRes = 0;
-  int rc = SQLITE_OK;
-
-  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
-  for(ii=0; bRes==0 && ii<pCursor->nConstraint; ii++){
-    RtreeConstraint *p = &pCursor->aConstraint[ii];
-    RtreeDValue cell_min = DCOORD(cell.aCoord[(p->iCoord>>1)*2]);
-    RtreeDValue cell_max = DCOORD(cell.aCoord[(p->iCoord>>1)*2+1]);
-
-    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
-        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
-    );
-
-    switch( p->op ){
-      case RTREE_LE: case RTREE_LT: 
-        bRes = p->rValue<cell_min; 
-        break;
-
-      case RTREE_GE: case RTREE_GT: 
-        bRes = p->rValue>cell_max; 
-        break;
-
-      case RTREE_EQ:
-        bRes = (p->rValue>cell_max || p->rValue<cell_min);
-        break;
-
-      default: {
-        assert( p->op==RTREE_MATCH );
-        rc = testRtreeGeom(pRtree, p, &cell, &bRes);
-        bRes = !bRes;
-        break;
-      }
+static int rtreeCallbackConstraint(
+  RtreeConstraint *pConstraint,  /* The constraint to test */
+  int eInt,                      /* True if RTree holding integer coordinates */
+  u8 *pCellData,                 /* Raw cell content */
+  RtreeSearchPoint *pSearch,     /* Container of this cell */
+  sqlite3_rtree_dbl *prScore,    /* OUT: score for the cell */
+  int *peWithin                  /* OUT: visibility of the cell */
+){
+  int i;                                                /* Loop counter */
+  sqlite3_rtree_query_info *pInfo = pConstraint->pInfo; /* Callback info */
+  int nCoord = pInfo->nCoord;                           /* No. of coordinates */
+  int rc;                                             /* Callback return code */
+  sqlite3_rtree_dbl aCoord[RTREE_MAX_DIMENSIONS*2];   /* Decoded coordinates */
+
+  assert( pConstraint->op==RTREE_MATCH || pConstraint->op==RTREE_QUERY );
+  assert( nCoord==2 || nCoord==4 || nCoord==6 || nCoord==8 || nCoord==10 );
+
+  if( pConstraint->op==RTREE_QUERY && pSearch->iLevel==1 ){
+    pInfo->iRowid = readInt64(pCellData);
+  }
+  pCellData += 8;
+  for(i=0; i<nCoord; i++, pCellData += 4){
+    RTREE_DECODE_COORD(eInt, pCellData, aCoord[i]);
+  }
+  if( pConstraint->op==RTREE_MATCH ){
+    rc = pConstraint->u.xGeom((sqlite3_rtree_geometry*)pInfo,
+                              nCoord, aCoord, &i);
+    if( i==0 ) *peWithin = NOT_WITHIN;
+    *prScore = RTREE_ZERO;
+  }else{
+    pInfo->aCoord = aCoord;
+    pInfo->iLevel = pSearch->iLevel - 1;
+    pInfo->rScore = pInfo->rParentScore = pSearch->rScore;
+    pInfo->eWithin = pInfo->eParentWithin = pSearch->eWithin;
+    rc = pConstraint->u.xQueryFunc(pInfo);
+    if( pInfo->eWithin<*peWithin ) *peWithin = pInfo->eWithin;
+    if( pInfo->rScore<*prScore || *prScore<RTREE_ZERO ){
+      *prScore = pInfo->rScore;
     }
   }
-
-  *pbEof = bRes;
   return rc;
 }
 
 /* 
-** Test if the cell that cursor pCursor currently points to
-** would be filtered (excluded) by the constraints in the 
-** pCursor->aConstraint[] array. If so, set *pbEof to true before
-** returning. If the cell is not filtered (excluded) by the constraints,
-** set pbEof to zero.
-**
-** Return SQLITE_OK if successful or an SQLite error code if an error
-** occurs within a geometry callback.
-**
-** This function assumes that the cell is part of a leaf node.
-*/
-static int testRtreeEntry(Rtree *pRtree, RtreeCursor *pCursor, int *pbEof){
-  RtreeCell cell;
-  int ii;
-  *pbEof = 0;
-
-  nodeGetCell(pRtree, pCursor->pNode, pCursor->iCell, &cell);
-  for(ii=0; ii<pCursor->nConstraint; ii++){
-    RtreeConstraint *p = &pCursor->aConstraint[ii];
-    RtreeDValue coord = DCOORD(cell.aCoord[p->iCoord]);
-    int res;
-    assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
-        || p->op==RTREE_GT || p->op==RTREE_EQ || p->op==RTREE_MATCH
-    );
-    switch( p->op ){
-      case RTREE_LE: res = (coord<=p->rValue); break;
-      case RTREE_LT: res = (coord<p->rValue);  break;
-      case RTREE_GE: res = (coord>=p->rValue); break;
-      case RTREE_GT: res = (coord>p->rValue);  break;
-      case RTREE_EQ: res = (coord==p->rValue); break;
-      default: {
-        int rc;
-        assert( p->op==RTREE_MATCH );
-        rc = testRtreeGeom(pRtree, p, &cell, &res);
-        if( rc!=SQLITE_OK ){
-          return rc;
-        }
-        break;
-      }
-    }
-
-    if( !res ){
-      *pbEof = 1;
-      return SQLITE_OK;
-    }
-  }
-
-  return SQLITE_OK;
-}
-
-/*
-** Cursor pCursor currently points at a node that heads a sub-tree of
-** height iHeight (if iHeight==0, then the node is a leaf). Descend
-** to point to the left-most cell of the sub-tree that matches the 
-** configured constraints.
-*/
-static int descendToCell(
-  Rtree *pRtree, 
-  RtreeCursor *pCursor, 
-  int iHeight,
-  int *pEof                 /* OUT: Set to true if cannot descend */
+** Check the internal RTree node given by pCellData against constraint p.
+** If this constraint cannot be satisfied by any child within the node,
+** set *peWithin to NOT_WITHIN.
+*/
+static void rtreeNonleafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
 ){
-  int isEof;
-  int rc;
-  int ii;
-  RtreeNode *pChild;
-  sqlite3_int64 iRowid;
-
-  RtreeNode *pSavedNode = pCursor->pNode;
-  int iSavedCell = pCursor->iCell;
+  sqlite3_rtree_dbl val;     /* Coordinate value convert to a double */
 
-  assert( iHeight>=0 );
+  /* p->iCoord might point to either a lower or upper bound coordinate
+  ** in a coordinate pair.  But make pCellData point to the lower bound.
+  */
+  pCellData += 8 + 4*(p->iCoord&0xfe);
 
-  if( iHeight==0 ){
-    rc = testRtreeEntry(pRtree, pCursor, &isEof);
-  }else{
-    rc = testRtreeCell(pRtree, pCursor, &isEof);
-  }
-  if( rc!=SQLITE_OK || isEof || iHeight==0 ){
-    goto descend_to_cell_out;
-  }
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  switch( p->op ){
+    case RTREE_LE:
+    case RTREE_LT:
+    case RTREE_EQ:
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the lower bound of the coordinate pair */
+      if( p->u.rValue>=val ) return;
+      if( p->op!=RTREE_EQ ) break;  /* RTREE_LE and RTREE_LT end here */
+      /* Fall through for the RTREE_EQ case */
 
-  iRowid = nodeGetRowid(pRtree, pCursor->pNode, pCursor->iCell);
-  rc = nodeAcquire(pRtree, iRowid, pCursor->pNode, &pChild);
-  if( rc!=SQLITE_OK ){
-    goto descend_to_cell_out;
+    default: /* RTREE_GT or RTREE_GE,  or fallthrough of RTREE_EQ */
+      pCellData += 4;
+      RTREE_DECODE_COORD(eInt, pCellData, val);
+      /* val now holds the upper bound of the coordinate pair */
+      if( p->u.rValue<=val ) return;
   }
+  *peWithin = NOT_WITHIN;
+}
 
-  nodeRelease(pRtree, pCursor->pNode);
-  pCursor->pNode = pChild;
-  isEof = 1;
-  for(ii=0; isEof && ii<NCELL(pChild); ii++){
-    pCursor->iCell = ii;
-    rc = descendToCell(pRtree, pCursor, iHeight-1, &isEof);
-    if( rc!=SQLITE_OK ){
-      goto descend_to_cell_out;
-    }
-  }
+/*
+** Check the leaf RTree cell given by pCellData against constraint p.
+** If this constraint is not satisfied, set *peWithin to NOT_WITHIN.
+** If the constraint is satisfied, leave *peWithin unchanged.
+**
+** The constraint is of the form:  xN op $val
+**
+** The op is given by p->op.  The xN is p->iCoord-th coordinate in
+** pCellData.  $val is given by p->u.rValue.
+*/
+static void rtreeLeafConstraint(
+  RtreeConstraint *p,        /* The constraint to test */
+  int eInt,                  /* True if RTree holds integer coordinates */
+  u8 *pCellData,             /* Raw cell content as appears on disk */
+  int *peWithin              /* Adjust downward, as appropriate */
+){
+  RtreeDValue xN;      /* Coordinate value converted to a double */
 
-  if( isEof ){
-    assert( pCursor->pNode==pChild );
-    nodeReference(pSavedNode);
-    nodeRelease(pRtree, pChild);
-    pCursor->pNode = pSavedNode;
-    pCursor->iCell = iSavedCell;
+  assert(p->op==RTREE_LE || p->op==RTREE_LT || p->op==RTREE_GE 
+      || p->op==RTREE_GT || p->op==RTREE_EQ );
+  pCellData += 8 + p->iCoord*4;
+  RTREE_DECODE_COORD(eInt, pCellData, xN);
+  switch( p->op ){
+    case RTREE_LE: if( xN <= p->u.rValue ) return;  break;
+    case RTREE_LT: if( xN <  p->u.rValue ) return;  break;
+    case RTREE_GE: if( xN >= p->u.rValue ) return;  break;
+    case RTREE_GT: if( xN >  p->u.rValue ) return;  break;
+    default:       if( xN == p->u.rValue ) return;  break;
   }
-
-descend_to_cell_out:
-  *pEof = isEof;
-  return rc;
+  *peWithin = NOT_WITHIN;
 }
 
 /*
@@ -1074,6 +1073,7 @@ static int nodeRowidIndex(
 ){
   int ii;
   int nCell = NCELL(pNode);
+  assert( nCell<200 );
   for(ii=0; ii<nCell; ii++){
     if( nodeGetRowid(pRtree, pNode, ii)==iRowid ){
       *piIndex = ii;
@@ -1096,48 +1096,302 @@ static int nodeParentIndex(Rtree *pRtree, RtreeNode *pNode, int *piIndex){
   return SQLITE_OK;
 }
 
-/* 
-** Rtree virtual table module xNext method.
+/*
+** Compare two search points.  Return negative, zero, or positive if the first
+** is less than, equal to, or greater than the second.
+**
+** The rScore is the primary key.  Smaller rScore values come first.
+** If the rScore is a tie, then use iLevel as the tie breaker with smaller
+** iLevel values coming first.  In this way, if rScore is the same for all
+** SearchPoints, then iLevel becomes the deciding factor and the result
+** is a depth-first search, which is the desired default behavior.
+*/
+static int rtreeSearchPointCompare(
+  const RtreeSearchPoint *pA,
+  const RtreeSearchPoint *pB
+){
+  if( pA->rScore<pB->rScore ) return -1;
+  if( pA->rScore>pB->rScore ) return +1;
+  if( pA->iLevel<pB->iLevel ) return -1;
+  if( pA->iLevel>pB->iLevel ) return +1;
+  return 0;
+}
+
+/*
+** Interchange to search points in a cursor.
+*/
+static void rtreeSearchPointSwap(RtreeCursor *p, int i, int j){
+  RtreeSearchPoint t = p->aPoint[i];
+  assert( i<j );
+  p->aPoint[i] = p->aPoint[j];
+  p->aPoint[j] = t;
+  i++; j++;
+  if( i<RTREE_CACHE_SZ ){
+    if( j>=RTREE_CACHE_SZ ){
+      nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+      p->aNode[i] = 0;
+    }else{
+      RtreeNode *pTemp = p->aNode[i];
+      p->aNode[i] = p->aNode[j];
+      p->aNode[j] = pTemp;
+    }
+  }
+}
+
+/*
+** Return the search point with the lowest current score.
 */
-static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
-  Rtree *pRtree = (Rtree *)(pVtabCursor->pVtab);
-  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-  int rc = SQLITE_OK;
+static RtreeSearchPoint *rtreeSearchPointFirst(RtreeCursor *pCur){
+  return pCur->bPoint ? &pCur->sPoint : pCur->nPoint ? pCur->aPoint : 0;
+}
 
-  /* RtreeCursor.pNode must not be NULL. If is is NULL, then this cursor is
-  ** already at EOF. It is against the rules to call the xNext() method of
-  ** a cursor that has already reached EOF.
-  */
-  assert( pCsr->pNode );
+/*
+** Get the RtreeNode for the search point with the lowest score.
+*/
+static RtreeNode *rtreeNodeOfFirstSearchPoint(RtreeCursor *pCur, int *pRC){
+  sqlite3_int64 id;
+  int ii = 1 - pCur->bPoint;
+  assert( ii==0 || ii==1 );
+  assert( pCur->bPoint || pCur->nPoint );
+  if( pCur->aNode[ii]==0 ){
+    assert( pRC!=0 );
+    id = ii ? pCur->aPoint[0].id : pCur->sPoint.id;
+    *pRC = nodeAcquire(RTREE_OF_CURSOR(pCur), id, 0, &pCur->aNode[ii]);
+  }
+  return pCur->aNode[ii];
+}
 
-  if( pCsr->iStrategy==1 ){
-    /* This "scan" is a direct lookup by rowid. There is no next entry. */
-    nodeRelease(pRtree, pCsr->pNode);
-    pCsr->pNode = 0;
+/*
+** Push a new element onto the priority queue
+*/
+static RtreeSearchPoint *rtreeEnqueue(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
+){
+  int i, j;
+  RtreeSearchPoint *pNew;
+  if( pCur->nPoint>=pCur->nPointAlloc ){
+    int nNew = pCur->nPointAlloc*2 + 8;
+    pNew = sqlite3_realloc(pCur->aPoint, nNew*sizeof(pCur->aPoint[0]));
+    if( pNew==0 ) return 0;
+    pCur->aPoint = pNew;
+    pCur->nPointAlloc = nNew;
+  }
+  i = pCur->nPoint++;
+  pNew = pCur->aPoint + i;
+  pNew->rScore = rScore;
+  pNew->iLevel = iLevel;
+  assert( iLevel>=0 && iLevel<=RTREE_MAX_DEPTH );
+  while( i>0 ){
+    RtreeSearchPoint *pParent;
+    j = (i-1)/2;
+    pParent = pCur->aPoint + j;
+    if( rtreeSearchPointCompare(pNew, pParent)>=0 ) break;
+    rtreeSearchPointSwap(pCur, j, i);
+    i = j;
+    pNew = pParent;
+  }
+  return pNew;
+}
+
+/*
+** Allocate a new RtreeSearchPoint and return a pointer to it.  Return
+** NULL if malloc fails.
+*/
+static RtreeSearchPoint *rtreeSearchPointNew(
+  RtreeCursor *pCur,    /* The cursor */
+  RtreeDValue rScore,   /* Score for the new search point */
+  u8 iLevel             /* Level for the new search point */
+){
+  RtreeSearchPoint *pNew, *pFirst;
+  pFirst = rtreeSearchPointFirst(pCur);
+  pCur->anQueue[iLevel]++;
+  if( pFirst==0
+   || pFirst->rScore>rScore 
+   || (pFirst->rScore==rScore && pFirst->iLevel>iLevel)
+  ){
+    if( pCur->bPoint ){
+      int ii;
+      pNew = rtreeEnqueue(pCur, rScore, iLevel);
+      if( pNew==0 ) return 0;
+      ii = (int)(pNew - pCur->aPoint) + 1;
+      if( ii<RTREE_CACHE_SZ ){
+        assert( pCur->aNode[ii]==0 );
+        pCur->aNode[ii] = pCur->aNode[0];
+       }else{
+        nodeRelease(RTREE_OF_CURSOR(pCur), pCur->aNode[0]);
+      }
+      pCur->aNode[0] = 0;
+      *pNew = pCur->sPoint;
+    }
+    pCur->sPoint.rScore = rScore;
+    pCur->sPoint.iLevel = iLevel;
+    pCur->bPoint = 1;
+    return &pCur->sPoint;
   }else{
-    /* Move to the next entry that matches the configured constraints. */
-    int iHeight = 0;
-    while( pCsr->pNode ){
-      RtreeNode *pNode = pCsr->pNode;
-      int nCell = NCELL(pNode);
-      for(pCsr->iCell++; pCsr->iCell<nCell; pCsr->iCell++){
-        int isEof;
-        rc = descendToCell(pRtree, pCsr, iHeight, &isEof);
-        if( rc!=SQLITE_OK || !isEof ){
-          return rc;
+    return rtreeEnqueue(pCur, rScore, iLevel);
+  }
+}
+
+#if 0
+/* Tracing routines for the RtreeSearchPoint queue */
+static void tracePoint(RtreeSearchPoint *p, int idx, RtreeCursor *pCur){
+  if( idx<0 ){ printf(" s"); }else{ printf("%2d", idx); }
+  printf(" %d.%05lld.%02d %g %d",
+    p->iLevel, p->id, p->iCell, p->rScore, p->eWithin
+  );
+  idx++;
+  if( idx<RTREE_CACHE_SZ ){
+    printf(" %p\n", pCur->aNode[idx]);
+  }else{
+    printf("\n");
+  }
+}
+static void traceQueue(RtreeCursor *pCur, const char *zPrefix){
+  int ii;
+  printf("=== %9s ", zPrefix);
+  if( pCur->bPoint ){
+    tracePoint(&pCur->sPoint, -1, pCur);
+  }
+  for(ii=0; ii<pCur->nPoint; ii++){
+    if( ii>0 || pCur->bPoint ) printf("              ");
+    tracePoint(&pCur->aPoint[ii], ii, pCur);
+  }
+}
+# define RTREE_QUEUE_TRACE(A,B) traceQueue(A,B)
+#else
+# define RTREE_QUEUE_TRACE(A,B)   /* no-op */
+#endif
+
+/* Remove the search point with the lowest current score.
+*/
+static void rtreeSearchPointPop(RtreeCursor *p){
+  int i, j, k, n;
+  i = 1 - p->bPoint;
+  assert( i==0 || i==1 );
+  if( p->aNode[i] ){
+    nodeRelease(RTREE_OF_CURSOR(p), p->aNode[i]);
+    p->aNode[i] = 0;
+  }
+  if( p->bPoint ){
+    p->anQueue[p->sPoint.iLevel]--;
+    p->bPoint = 0;
+  }else if( p->nPoint ){
+    p->anQueue[p->aPoint[0].iLevel]--;
+    n = --p->nPoint;
+    p->aPoint[0] = p->aPoint[n];
+    if( n<RTREE_CACHE_SZ-1 ){
+      p->aNode[1] = p->aNode[n+1];
+      p->aNode[n+1] = 0;
+    }
+    i = 0;
+    while( (j = i*2+1)<n ){
+      k = j+1;
+      if( k<n && rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[j])<0 ){
+        if( rtreeSearchPointCompare(&p->aPoint[k], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, k);
+          i = k;
+        }else{
+          break;
+        }
+      }else{
+        if( rtreeSearchPointCompare(&p->aPoint[j], &p->aPoint[i])<0 ){
+          rtreeSearchPointSwap(p, i, j);
+          i = j;
+        }else{
+          break;
         }
       }
-      pCsr->pNode = pNode->pParent;
-      rc = nodeParentIndex(pRtree, pNode, &pCsr->iCell);
-      if( rc!=SQLITE_OK ){
-        return rc;
+    }
+  }
+}
+
+
+/*
+** Continue the search on cursor pCur until the front of the queue
+** contains an entry suitable for returning as a result-set row,
+** or until the RtreeSearchPoint queue is empty, indicating that the
+** query has completed.
+*/
+static int rtreeStepToLeaf(RtreeCursor *pCur){
+  RtreeSearchPoint *p;
+  Rtree *pRtree = RTREE_OF_CURSOR(pCur);
+  RtreeNode *pNode;
+  int eWithin;
+  int rc = SQLITE_OK;
+  int nCell;
+  int nConstraint = pCur->nConstraint;
+  int ii;
+  int eInt;
+  RtreeSearchPoint x;
+
+  eInt = pRtree->eCoordType==RTREE_COORD_INT32;
+  while( (p = rtreeSearchPointFirst(pCur))!=0 && p->iLevel>0 ){
+    pNode = rtreeNodeOfFirstSearchPoint(pCur, &rc);
+    if( rc ) return rc;
+    nCell = NCELL(pNode);
+    assert( nCell<200 );
+    while( p->iCell<nCell ){
+      sqlite3_rtree_dbl rScore = (sqlite3_rtree_dbl)-1;
+      u8 *pCellData = pNode->zData + (4+pRtree->nBytesPerCell*p->iCell);
+      eWithin = FULLY_WITHIN;
+      for(ii=0; ii<nConstraint; ii++){
+        RtreeConstraint *pConstraint = pCur->aConstraint + ii;
+        if( pConstraint->op>=RTREE_MATCH ){
+          rc = rtreeCallbackConstraint(pConstraint, eInt, pCellData, p,
+                                       &rScore, &eWithin);
+          if( rc ) return rc;
+        }else if( p->iLevel==1 ){
+          rtreeLeafConstraint(pConstraint, eInt, pCellData, &eWithin);
+        }else{
+          rtreeNonleafConstraint(pConstraint, eInt, pCellData, &eWithin);
+        }
+        if( eWithin==NOT_WITHIN ) break;
+      }
+      p->iCell++;
+      if( eWithin==NOT_WITHIN ) continue;
+      x.iLevel = p->iLevel - 1;
+      if( x.iLevel ){
+        x.id = readInt64(pCellData);
+        x.iCell = 0;
+      }else{
+        x.id = p->id;
+        x.iCell = p->iCell - 1;
+      }
+      if( p->iCell>=nCell ){
+        RTREE_QUEUE_TRACE(pCur, "POP-S:");
+        rtreeSearchPointPop(pCur);
       }
-      nodeReference(pCsr->pNode);
-      nodeRelease(pRtree, pNode);
-      iHeight++;
+      if( rScore<RTREE_ZERO ) rScore = RTREE_ZERO;
+      p = rtreeSearchPointNew(pCur, rScore, x.iLevel);
+      if( p==0 ) return SQLITE_NOMEM;
+      p->eWithin = eWithin;
+      p->id = x.id;
+      p->iCell = x.iCell;
+      RTREE_QUEUE_TRACE(pCur, "PUSH-S:");
+      break;
+    }
+    if( p->iCell>=nCell ){
+      RTREE_QUEUE_TRACE(pCur, "POP-Se:");
+      rtreeSearchPointPop(pCur);
     }
   }
+  pCur->atEOF = p==0;
+  return SQLITE_OK;
+}
 
+/* 
+** Rtree virtual table module xNext method.
+*/
+static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
+  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
+  int rc = SQLITE_OK;
+
+  /* Move to the next entry that matches the configured constraints. */
+  RTREE_QUEUE_TRACE(pCsr, "POP-Nx:");
+  rtreeSearchPointPop(pCsr);
+  rc = rtreeStepToLeaf(pCsr);
   return rc;
 }
 
@@ -1145,13 +1399,14 @@ static int rtreeNext(sqlite3_vtab_cursor *pVtabCursor){
 ** Rtree virtual table module xRowid method.
 */
 static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
-  Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-
-  assert(pCsr->pNode);
-  *pRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
-
-  return SQLITE_OK;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
+  if( rc==SQLITE_OK && p ){
+    *pRowid = nodeGetRowid(RTREE_OF_CURSOR(pCsr), pNode, p->iCell);
+  }
+  return rc;
 }
 
 /* 
@@ -1160,13 +1415,18 @@ static int rtreeRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
 static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
   Rtree *pRtree = (Rtree *)cur->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)cur;
+  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
+  RtreeCoord c;
+  int rc = SQLITE_OK;
+  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);
 
+  if( rc ) return rc;
+  if( p==0 ) return SQLITE_OK;
   if( i==0 ){
-    i64 iRowid = nodeGetRowid(pRtree, pCsr->pNode, pCsr->iCell);
-    sqlite3_result_int64(ctx, iRowid);
+    sqlite3_result_int64(ctx, nodeGetRowid(pRtree, pNode, p->iCell));
   }else{
-    RtreeCoord c;
-    nodeGetCoord(pRtree, pCsr->pNode, pCsr->iCell, i-1, &c);
+    if( rc ) return rc;
+    nodeGetCoord(pRtree, pNode, p->iCell, i-1, &c);
 #ifndef SQLITE_RTREE_INT_ONLY
     if( pRtree->eCoordType==RTREE_COORD_REAL32 ){
       sqlite3_result_double(ctx, c.f);
@@ -1177,7 +1437,6 @@ static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
       sqlite3_result_int(ctx, c.i);
     }
   }
-
   return SQLITE_OK;
 }
 
@@ -1188,12 +1447,18 @@ static int rtreeColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
 ** *ppLeaf to 0 and return SQLITE_OK. If an error occurs, set *ppLeaf
 ** to zero and return an SQLite error code.
 */
-static int findLeafNode(Rtree *pRtree, i64 iRowid, RtreeNode **ppLeaf){
+static int findLeafNode(
+  Rtree *pRtree,              /* RTree to search */
+  i64 iRowid,                 /* The rowid searching for */
+  RtreeNode **ppLeaf,         /* Write the node here */
+  sqlite3_int64 *piNode       /* Write the node-id here */
+){
   int rc;
   *ppLeaf = 0;
   sqlite3_bind_int64(pRtree->pReadRowid, 1, iRowid);
   if( sqlite3_step(pRtree->pReadRowid)==SQLITE_ROW ){
     i64 iNode = sqlite3_column_int64(pRtree->pReadRowid, 0);
+    if( piNode ) *piNode = iNode;
     rc = nodeAcquire(pRtree, iNode, 0, ppLeaf);
     sqlite3_reset(pRtree->pReadRowid);
   }else{
@@ -1209,9 +1474,10 @@ static int findLeafNode(Rtree *pRtree, i64 iRowid, RtreeNode **ppLeaf){
 ** operator.
 */
 static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
-  RtreeMatchArg *p;
-  sqlite3_rtree_geometry *pGeom;
-  int nBlob;
+  RtreeMatchArg *pBlob;              /* BLOB returned by geometry function */
+  sqlite3_rtree_query_info *pInfo;   /* Callback information */
+  int nBlob;                         /* Size of the geometry function blob */
+  int nExpected;                     /* Expected size of the BLOB */
 
   /* Check that value is actually a blob. */
   if( sqlite3_value_type(pValue)!=SQLITE_BLOB ) return SQLITE_ERROR;
@@ -1224,27 +1490,29 @@ static int deserializeGeometry(sqlite3_value *pValue, RtreeConstraint *pCons){
     return SQLITE_ERROR;
   }
 
-  pGeom = (sqlite3_rtree_geometry *)sqlite3_malloc(
-      sizeof(sqlite3_rtree_geometry) + nBlob
-  );
-  if( !pGeom ) return SQLITE_NOMEM;
-  memset(pGeom, 0, sizeof(sqlite3_rtree_geometry));
-  p = (RtreeMatchArg *)&pGeom[1];
+  pInfo = (sqlite3_rtree_query_info*)sqlite3_malloc( sizeof(*pInfo)+nBlob );
+  if( !pInfo ) return SQLITE_NOMEM;
+  memset(pInfo, 0, sizeof(*pInfo));
+  pBlob = (RtreeMatchArg*)&pInfo[1];
 
-  memcpy(p, sqlite3_value_blob(pValue), nBlob);
-  if( p->magic!=RTREE_GEOMETRY_MAGIC 
-   || nBlob!=(int)(sizeof(RtreeMatchArg) + (p->nParam-1)*sizeof(RtreeDValue))
-  ){
-    sqlite3_free(pGeom);
+  memcpy(pBlob, sqlite3_value_blob(pValue), nBlob);
+  nExpected = (int)(sizeof(RtreeMatchArg) +
+                    (pBlob->nParam-1)*sizeof(RtreeDValue));
+  if( pBlob->magic!=RTREE_GEOMETRY_MAGIC || nBlob!=nExpected ){
+    sqlite3_free(pInfo);
     return SQLITE_ERROR;
   }
+  pInfo->pContext = pBlob->cb.pContext;
+  pInfo->nParam = pBlob->nParam;
+  pInfo->aParam = pBlob->aParam;
 
-  pGeom->pContext = p->pContext;
-  pGeom->nParam = p->nParam;
-  pGeom->aParam = p->aParam;
-
-  pCons->xGeom = p->xGeom;
-  pCons->pGeom = pGeom;
+  if( pBlob->cb.xGeom ){
+    pCons->u.xGeom = pBlob->cb.xGeom;
+  }else{
+    pCons->op = RTREE_QUERY;
+    pCons->u.xQueryFunc = pBlob->cb.xQueryFunc;
+  }
+  pCons->pInfo = pInfo;
   return SQLITE_OK;
 }
 
@@ -1258,44 +1526,59 @@ static int rtreeFilter(
 ){
   Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
   RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
-
   RtreeNode *pRoot = 0;
   int ii;
   int rc = SQLITE_OK;
+  int iCell = 0;
 
   rtreeReference(pRtree);
 
+  /* Reset the cursor to the same state as rtreeOpen() leaves it in. */
   freeCursorConstraints(pCsr);
-  pCsr->iStrategy = idxNum;
+  sqlite3_free(pCsr->aPoint);
+  memset(pCsr, 0, sizeof(RtreeCursor));
+  pCsr->base.pVtab = (sqlite3_vtab*)pRtree;
 
+  pCsr->iStrategy = idxNum;
   if( idxNum==1 ){
     /* Special case - lookup by rowid. */
     RtreeNode *pLeaf;        /* Leaf on which the required cell resides */
+    RtreeSearchPoint *p;     /* Search point for the the leaf */
     i64 iRowid = sqlite3_value_int64(argv[0]);
-    rc = findLeafNode(pRtree, iRowid, &pLeaf);
-    pCsr->pNode = pLeaf; 
-    if( pLeaf ){
-      assert( rc==SQLITE_OK );
-      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &pCsr->iCell);
+    i64 iNode = 0;
+    rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);
+    if( rc==SQLITE_OK && pLeaf!=0 ){
+      p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);
+      assert( p!=0 );  /* Always returns pCsr->sPoint */
+      pCsr->aNode[0] = pLeaf;
+      p->id = iNode;
+      p->eWithin = PARTLY_WITHIN;
+      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);
+      p->iCell = iCell;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");
+    }else{
+      pCsr->atEOF = 1;
     }
   }else{
     /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 
     ** with the configured constraints. 
     */
-    if( argc>0 ){
+    rc = nodeAcquire(pRtree, 1, 0, &pRoot);
+    if( rc==SQLITE_OK && argc>0 ){
       pCsr->aConstraint = sqlite3_malloc(sizeof(RtreeConstraint)*argc);
       pCsr->nConstraint = argc;
       if( !pCsr->aConstraint ){
         rc = SQLITE_NOMEM;
       }else{
         memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*argc);
+        memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));
         assert( (idxStr==0 && argc==0)
                 || (idxStr && (int)strlen(idxStr)==argc*2) );
         for(ii=0; ii<argc; ii++){
           RtreeConstraint *p = &pCsr->aConstraint[ii];
           p->op = idxStr[ii*2];
-          p->iCoord = idxStr[ii*2+1]-'a';
-          if( p->op==RTREE_MATCH ){
+          p->iCoord = idxStr[ii*2+1]-'0';
+          if( p->op>=RTREE_MATCH ){
             /* A MATCH operator. The right-hand-side must be a blob that
             ** can be cast into an RtreeMatchArg object. One created using
             ** an sqlite3_rtree_geometry_callback() SQL user function.
@@ -1304,46 +1587,53 @@ static int rtreeFilter(
             if( rc!=SQLITE_OK ){
               break;
             }
+            p->pInfo->nCoord = pRtree->nDim*2;
+            p->pInfo->anQueue = pCsr->anQueue;
+            p->pInfo->mxLevel = pRtree->iDepth + 1;
           }else{
 #ifdef SQLITE_RTREE_INT_ONLY
-            p->rValue = sqlite3_value_int64(argv[ii]);
+            p->u.rValue = sqlite3_value_int64(argv[ii]);
 #else
-            p->rValue = sqlite3_value_double(argv[ii]);
+            p->u.rValue = sqlite3_value_double(argv[ii]);
 #endif
           }
         }
       }
     }
-  
     if( rc==SQLITE_OK ){
-      pCsr->pNode = 0;
-      rc = nodeAcquire(pRtree, 1, 0, &pRoot);
-    }
-    if( rc==SQLITE_OK ){
-      int isEof = 1;
-      int nCell = NCELL(pRoot);
-      pCsr->pNode = pRoot;
-      for(pCsr->iCell=0; rc==SQLITE_OK && pCsr->iCell<nCell; pCsr->iCell++){
-        assert( pCsr->pNode==pRoot );
-        rc = descendToCell(pRtree, pCsr, pRtree->iDepth, &isEof);
-        if( !isEof ){
-          break;
-        }
-      }
-      if( rc==SQLITE_OK && isEof ){
-        assert( pCsr->pNode==pRoot );
-        nodeRelease(pRtree, pRoot);
-        pCsr->pNode = 0;
-      }
-      assert( rc!=SQLITE_OK || !pCsr->pNode || pCsr->iCell<NCELL(pCsr->pNode) );
+      RtreeSearchPoint *pNew;
+      pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, pRtree->iDepth+1);
+      if( pNew==0 ) return SQLITE_NOMEM;
+      pNew->id = 1;
+      pNew->iCell = 0;
+      pNew->eWithin = PARTLY_WITHIN;
+      assert( pCsr->bPoint==1 );
+      pCsr->aNode[0] = pRoot;
+      pRoot = 0;
+      RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");
+      rc = rtreeStepToLeaf(pCsr);
     }
   }
 
+  nodeRelease(pRtree, pRoot);
   rtreeRelease(pRtree);
   return rc;
 }
 
 /*
+** Set the pIdxInfo->estimatedRows variable to nRow. Unless this
+** extension is currently being used by a version of SQLite too old to
+** support estimatedRows. In that case this function is a no-op.
+*/
+static void setEstimatedRows(sqlite3_index_info *pIdxInfo, i64 nRow){
+#if SQLITE_VERSION_NUMBER>=3008002
+  if( sqlite3_libversion_number()>=3008002 ){
+    pIdxInfo->estimatedRows = nRow;
+  }
+#endif
+}
+
+/*
 ** Rtree virtual table module xBestIndex method. There are three
 ** table scan strategies to choose from (in order from most to 
 ** least desirable):
@@ -1378,13 +1668,14 @@ static int rtreeFilter(
 ** is 'a', the second from the left 'b' etc.
 */
 static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
+  Rtree *pRtree = (Rtree*)tab;
   int rc = SQLITE_OK;
   int ii;
+  i64 nRow;                       /* Estimated rows returned by this scan */
 
   int iIdx = 0;
   char zIdxStr[RTREE_MAX_DIMENSIONS*8+1];
   memset(zIdxStr, 0, sizeof(zIdxStr));
-  UNUSED_PARAMETER(tab);
 
   assert( pIdxInfo->idxStr==0 );
   for(ii=0; ii<pIdxInfo->nConstraint && iIdx<(int)(sizeof(zIdxStr)-1); ii++){
@@ -1404,9 +1695,11 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       /* This strategy involves a two rowid lookups on an B-Tree structures
       ** and then a linear search of an R-Tree node. This should be 
       ** considered almost as quick as a direct rowid lookup (for which 
-      ** sqlite uses an internal cost of 0.0).
+      ** sqlite uses an internal cost of 0.0). It is expected to return
+      ** a single row.
       */ 
-      pIdxInfo->estimatedCost = 10.0;
+      pIdxInfo->estimatedCost = 30.0;
+      setEstimatedRows(pIdxInfo, 1);
       return SQLITE_OK;
     }
 
@@ -1424,7 +1717,7 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
           break;
       }
       zIdxStr[iIdx++] = op;
-      zIdxStr[iIdx++] = p->iColumn - 1 + 'a';
+      zIdxStr[iIdx++] = p->iColumn - 1 + '0';
       pIdxInfo->aConstraintUsage[ii].argvIndex = (iIdx/2);
       pIdxInfo->aConstraintUsage[ii].omit = 1;
     }
@@ -1435,8 +1728,11 @@ static int rtreeBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   if( iIdx>0 && 0==(pIdxInfo->idxStr = sqlite3_mprintf("%s", zIdxStr)) ){
     return SQLITE_NOMEM;
   }
-  assert( iIdx>=0 );
-  pIdxInfo->estimatedCost = (2000000.0 / (double)(iIdx + 1));
+
+  nRow = pRtree->nRowEst / (iIdx + 1);
+  pIdxInfo->estimatedCost = (double)6.0 * (double)nRow;
+  setEstimatedRows(pIdxInfo, nRow);
+
   return rc;
 }
 
@@ -1514,62 +1810,32 @@ static RtreeDValue cellGrowth(Rtree *pRtree, RtreeCell *p, RtreeCell *pCell){
   return (cellArea(pRtree, &cell)-area);
 }
 
-#if VARIANT_RSTARTREE_CHOOSESUBTREE || VARIANT_RSTARTREE_SPLIT
 static RtreeDValue cellOverlap(
   Rtree *pRtree, 
   RtreeCell *p, 
   RtreeCell *aCell, 
-  int nCell, 
-  int iExclude
+  int nCell
 ){
   int ii;
-  RtreeDValue overlap = 0.0;
+  RtreeDValue overlap = RTREE_ZERO;
   for(ii=0; ii<nCell; ii++){
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    if( ii!=iExclude )
-#else
-    assert( iExclude==-1 );
-    UNUSED_PARAMETER(iExclude);
-#endif
-    {
-      int jj;
-      RtreeDValue o = (RtreeDValue)1;
-      for(jj=0; jj<(pRtree->nDim*2); jj+=2){
-        RtreeDValue x1, x2;
-
-        x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
-        x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
-
-        if( x2<x1 ){
-          o = 0.0;
-          break;
-        }else{
-          o = o * (x2-x1);
-        }
+    int jj;
+    RtreeDValue o = (RtreeDValue)1;
+    for(jj=0; jj<(pRtree->nDim*2); jj+=2){
+      RtreeDValue x1, x2;
+      x1 = MAX(DCOORD(p->aCoord[jj]), DCOORD(aCell[ii].aCoord[jj]));
+      x2 = MIN(DCOORD(p->aCoord[jj+1]), DCOORD(aCell[ii].aCoord[jj+1]));
+      if( x2<x1 ){
+        o = (RtreeDValue)0;
+        break;
+      }else{
+        o = o * (x2-x1);
       }
-      overlap += o;
     }
+    overlap += o;
   }
   return overlap;
 }
-#endif
-
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-static RtreeDValue cellOverlapEnlargement(
-  Rtree *pRtree, 
-  RtreeCell *p, 
-  RtreeCell *pInsert, 
-  RtreeCell *aCell, 
-  int nCell, 
-  int iExclude
-){
-  RtreeDValue before, after;
-  before = cellOverlap(pRtree, p, aCell, nCell, iExclude);
-  cellUnion(pRtree, p, pInsert);
-  after = cellOverlap(pRtree, p, aCell, nCell, iExclude);
-  return (after-before);
-}
-#endif
 
 
 /*
@@ -1591,12 +1857,8 @@ static int ChooseLeaf(
     int iCell;
     sqlite3_int64 iBest = 0;
 
-    RtreeDValue fMinGrowth = 0.0;
-    RtreeDValue fMinArea = 0.0;
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    RtreeDValue fMinOverlap = 0.0;
-    RtreeDValue overlap;
-#endif
+    RtreeDValue fMinGrowth = RTREE_ZERO;
+    RtreeDValue fMinArea = RTREE_ZERO;
 
     int nCell = NCELL(pNode);
     RtreeCell cell;
@@ -1604,22 +1866,6 @@ static int ChooseLeaf(
 
     RtreeCell *aCell = 0;
 
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-    if( ii==(pRtree->iDepth-1) ){
-      int jj;
-      aCell = sqlite3_malloc(sizeof(RtreeCell)*nCell);
-      if( !aCell ){
-        rc = SQLITE_NOMEM;
-        nodeRelease(pRtree, pNode);
-        pNode = 0;
-        continue;
-      }
-      for(jj=0; jj<nCell; jj++){
-        nodeGetCell(pRtree, pNode, jj, &aCell[jj]);
-      }
-    }
-#endif
-
     /* Select the child node which will be enlarged the least if pCell
     ** is inserted into it. Resolve ties by choosing the entry with
     ** the smallest area.
@@ -1631,26 +1877,9 @@ static int ChooseLeaf(
       nodeGetCell(pRtree, pNode, iCell, &cell);
       growth = cellGrowth(pRtree, &cell, pCell);
       area = cellArea(pRtree, &cell);
-
-#if VARIANT_RSTARTREE_CHOOSESUBTREE
-      if( ii==(pRtree->iDepth-1) ){
-        overlap = cellOverlapEnlargement(pRtree,&cell,pCell,aCell,nCell,iCell);
-      }else{
-        overlap = 0.0;
-      }
-      if( (iCell==0) 
-       || (overlap<fMinOverlap) 
-       || (overlap==fMinOverlap && growth<fMinGrowth)
-       || (overlap==fMinOverlap && growth==fMinGrowth && area<fMinArea)
-      ){
-        bBest = 1;
-        fMinOverlap = overlap;
-      }
-#else
       if( iCell==0||growth<fMinGrowth||(growth==fMinGrowth && area<fMinArea) ){
         bBest = 1;
       }
-#endif
       if( bBest ){
         fMinGrowth = growth;
         fMinArea = area;
@@ -1721,155 +1950,6 @@ static int parentWrite(Rtree *pRtree, sqlite3_int64 iNode, sqlite3_int64 iPar){
 
 static int rtreeInsertCell(Rtree *, RtreeNode *, RtreeCell *, int);
 
-#if VARIANT_GUTTMAN_LINEAR_SPLIT
-/*
-** Implementation of the linear variant of the PickNext() function from
-** Guttman[84].
-*/
-static RtreeCell *LinearPickNext(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  RtreeCell *pLeftBox, 
-  RtreeCell *pRightBox,
-  int *aiUsed
-){
-  int ii;
-  for(ii=0; aiUsed[ii]; ii++);
-  aiUsed[ii] = 1;
-  return &aCell[ii];
-}
-
-/*
-** Implementation of the linear variant of the PickSeeds() function from
-** Guttman[84].
-*/
-static void LinearPickSeeds(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  int *piLeftSeed, 
-  int *piRightSeed
-){
-  int i;
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  RtreeDValue maxNormalInnerWidth = (RtreeDValue)0;
-
-  /* Pick two "seed" cells from the array of cells. The algorithm used
-  ** here is the LinearPickSeeds algorithm from Gutman[1984]. The 
-  ** indices of the two seed cells in the array are stored in local
-  ** variables iLeftSeek and iRightSeed.
-  */
-  for(i=0; i<pRtree->nDim; i++){
-    RtreeDValue x1 = DCOORD(aCell[0].aCoord[i*2]);
-    RtreeDValue x2 = DCOORD(aCell[0].aCoord[i*2+1]);
-    RtreeDValue x3 = x1;
-    RtreeDValue x4 = x2;
-    int jj;
-
-    int iCellLeft = 0;
-    int iCellRight = 0;
-
-    for(jj=1; jj<nCell; jj++){
-      RtreeDValue left = DCOORD(aCell[jj].aCoord[i*2]);
-      RtreeDValue right = DCOORD(aCell[jj].aCoord[i*2+1]);
-
-      if( left<x1 ) x1 = left;
-      if( right>x4 ) x4 = right;
-      if( left>x3 ){
-        x3 = left;
-        iCellRight = jj;
-      }
-      if( right<x2 ){
-        x2 = right;
-        iCellLeft = jj;
-      }
-    }
-
-    if( x4!=x1 ){
-      RtreeDValue normalwidth = (x3 - x2) / (x4 - x1);
-      if( normalwidth>maxNormalInnerWidth ){
-        iLeftSeed = iCellLeft;
-        iRightSeed = iCellRight;
-      }
-    }
-  }
-
-  *piLeftSeed = iLeftSeed;
-  *piRightSeed = iRightSeed;
-}
-#endif /* VARIANT_GUTTMAN_LINEAR_SPLIT */
-
-#if VARIANT_GUTTMAN_QUADRATIC_SPLIT
-/*
-** Implementation of the quadratic variant of the PickNext() function from
-** Guttman[84].
-*/
-static RtreeCell *QuadraticPickNext(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  RtreeCell *pLeftBox, 
-  RtreeCell *pRightBox,
-  int *aiUsed
-){
-  #define FABS(a) ((a)<0.0?-1.0*(a):(a))
-
-  int iSelect = -1;
-  RtreeDValue fDiff;
-  int ii;
-  for(ii=0; ii<nCell; ii++){
-    if( aiUsed[ii]==0 ){
-      RtreeDValue left = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
-      RtreeDValue right = cellGrowth(pRtree, pLeftBox, &aCell[ii]);
-      RtreeDValue diff = FABS(right-left);
-      if( iSelect<0 || diff>fDiff ){
-        fDiff = diff;
-        iSelect = ii;
-      }
-    }
-  }
-  aiUsed[iSelect] = 1;
-  return &aCell[iSelect];
-}
-
-/*
-** Implementation of the quadratic variant of the PickSeeds() function from
-** Guttman[84].
-*/
-static void QuadraticPickSeeds(
-  Rtree *pRtree,
-  RtreeCell *aCell, 
-  int nCell, 
-  int *piLeftSeed, 
-  int *piRightSeed
-){
-  int ii;
-  int jj;
-
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  RtreeDValue fWaste = 0.0;
-
-  for(ii=0; ii<nCell; ii++){
-    for(jj=ii+1; jj<nCell; jj++){
-      RtreeDValue right = cellArea(pRtree, &aCell[jj]);
-      RtreeDValue growth = cellGrowth(pRtree, &aCell[ii], &aCell[jj]);
-      RtreeDValue waste = growth - right;
-
-      if( waste>fWaste ){
-        iLeftSeed = ii;
-        iRightSeed = jj;
-        fWaste = waste;
-      }
-    }
-  }
-
-  *piLeftSeed = iLeftSeed;
-  *piRightSeed = iRightSeed;
-}
-#endif /* VARIANT_GUTTMAN_QUADRATIC_SPLIT */
 
 /*
 ** Arguments aIdx, aDistance and aSpare all point to arrays of size
@@ -2010,7 +2090,6 @@ static void SortByDimension(
   }
 }
 
-#if VARIANT_RSTARTREE_SPLIT
 /*
 ** Implementation of the R*-tree variant of SplitNode from Beckman[1990].
 */
@@ -2029,7 +2108,7 @@ static int splitNodeStartree(
 
   int iBestDim = 0;
   int iBestSplit = 0;
-  RtreeDValue fBestMargin = 0.0;
+  RtreeDValue fBestMargin = RTREE_ZERO;
 
   int nByte = (pRtree->nDim+1)*(sizeof(int*)+nCell*sizeof(int));
 
@@ -2050,9 +2129,9 @@ static int splitNodeStartree(
   }
 
   for(ii=0; ii<pRtree->nDim; ii++){
-    RtreeDValue margin = 0.0;
-    RtreeDValue fBestOverlap = 0.0;
-    RtreeDValue fBestArea = 0.0;
+    RtreeDValue margin = RTREE_ZERO;
+    RtreeDValue fBestOverlap = RTREE_ZERO;
+    RtreeDValue fBestArea = RTREE_ZERO;
     int iBestLeft = 0;
     int nLeft;
 
@@ -2078,7 +2157,7 @@ static int splitNodeStartree(
       }
       margin += cellMargin(pRtree, &left);
       margin += cellMargin(pRtree, &right);
-      overlap = cellOverlap(pRtree, &left, &right, 1, -1);
+      overlap = cellOverlap(pRtree, &left, &right, 1);
       area = cellArea(pRtree, &left) + cellArea(pRtree, &right);
       if( (nLeft==RTREE_MINCELLS(pRtree))
        || (overlap<fBestOverlap)
@@ -2110,63 +2189,7 @@ static int splitNodeStartree(
   sqlite3_free(aaSorted);
   return SQLITE_OK;
 }
-#endif
 
-#if VARIANT_GUTTMAN_SPLIT
-/*
-** Implementation of the regular R-tree SplitNode from Guttman[1984].
-*/
-static int splitNodeGuttman(
-  Rtree *pRtree,
-  RtreeCell *aCell,
-  int nCell,
-  RtreeNode *pLeft,
-  RtreeNode *pRight,
-  RtreeCell *pBboxLeft,
-  RtreeCell *pBboxRight
-){
-  int iLeftSeed = 0;
-  int iRightSeed = 1;
-  int *aiUsed;
-  int i;
-
-  aiUsed = sqlite3_malloc(sizeof(int)*nCell);
-  if( !aiUsed ){
-    return SQLITE_NOMEM;
-  }
-  memset(aiUsed, 0, sizeof(int)*nCell);
-
-  PickSeeds(pRtree, aCell, nCell, &iLeftSeed, &iRightSeed);
-
-  memcpy(pBboxLeft, &aCell[iLeftSeed], sizeof(RtreeCell));
-  memcpy(pBboxRight, &aCell[iRightSeed], sizeof(RtreeCell));
-  nodeInsertCell(pRtree, pLeft, &aCell[iLeftSeed]);
-  nodeInsertCell(pRtree, pRight, &aCell[iRightSeed]);
-  aiUsed[iLeftSeed] = 1;
-  aiUsed[iRightSeed] = 1;
-
-  for(i=nCell-2; i>0; i--){
-    RtreeCell *pNext;
-    pNext = PickNext(pRtree, aCell, nCell, pBboxLeft, pBboxRight, aiUsed);
-    RtreeDValue diff =  
-      cellGrowth(pRtree, pBboxLeft, pNext) - 
-      cellGrowth(pRtree, pBboxRight, pNext)
-    ;
-    if( (RTREE_MINCELLS(pRtree)-NCELL(pRight)==i)
-     || (diff>0.0 && (RTREE_MINCELLS(pRtree)-NCELL(pLeft)!=i))
-    ){
-      nodeInsertCell(pRtree, pRight, pNext);
-      cellUnion(pRtree, pBboxRight, pNext);
-    }else{
-      nodeInsertCell(pRtree, pLeft, pNext);
-      cellUnion(pRtree, pBboxLeft, pNext);
-    }
-  }
-
-  sqlite3_free(aiUsed);
-  return SQLITE_OK;
-}
-#endif
 
 static int updateMapping(
   Rtree *pRtree, 
@@ -2244,7 +2267,8 @@ static int SplitNode(
   memset(pLeft->zData, 0, pRtree->iNodeSize);
   memset(pRight->zData, 0, pRtree->iNodeSize);
 
-  rc = AssignCells(pRtree, aCell, nCell, pLeft, pRight, &leftbbox, &rightbbox);
+  rc = splitNodeStartree(pRtree, aCell, nCell, pLeft, pRight,
+                         &leftbbox, &rightbbox);
   if( rc!=SQLITE_OK ){
     goto splitnode_out;
   }
@@ -2527,7 +2551,7 @@ static int Reinsert(
   }
 
   for(ii=0; ii<nCell; ii++){
-    aDistance[ii] = 0.0;
+    aDistance[ii] = RTREE_ZERO;
     for(iDim=0; iDim<pRtree->nDim; iDim++){
       RtreeDValue coord = (DCOORD(aCell[ii].aCoord[iDim*2+1]) - 
                                DCOORD(aCell[ii].aCoord[iDim*2]));
@@ -2593,16 +2617,12 @@ static int rtreeInsertCell(
     }
   }
   if( nodeInsertCell(pRtree, pNode, pCell) ){
-#if VARIANT_RSTARTREE_REINSERT
     if( iHeight<=pRtree->iReinsertHeight || pNode->iNode==1){
       rc = SplitNode(pRtree, pNode, pCell, iHeight);
     }else{
       pRtree->iReinsertHeight = iHeight;
       rc = Reinsert(pRtree, pNode, pCell, iHeight);
     }
-#else
-    rc = SplitNode(pRtree, pNode, pCell, iHeight);
-#endif
   }else{
     rc = AdjustTree(pRtree, pNode, pCell);
     if( rc==SQLITE_OK ){
@@ -2672,7 +2692,7 @@ static int rtreeDeleteRowid(Rtree *pRtree, sqlite3_int64 iDelete){
   ** about to be deleted. 
   */
   if( rc==SQLITE_OK ){
-    rc = findLeafNode(pRtree, iDelete, &pLeaf);
+    rc = findLeafNode(pRtree, iDelete, &pLeaf, 0);
   }
 
   /* Delete the cell in question from the leaf node. */
@@ -2911,6 +2931,43 @@ static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
   return rc;
 }
 
+/*
+** This function populates the pRtree->nRowEst variable with an estimate
+** of the number of rows in the virtual table. If possible, this is based
+** on sqlite_stat1 data. Otherwise, use RTREE_DEFAULT_ROWEST.
+*/
+static int rtreeQueryStat1(sqlite3 *db, Rtree *pRtree){
+  const char *zFmt = "SELECT stat FROM %Q.sqlite_stat1 WHERE tbl = '%q_rowid'";
+  char *zSql;
+  sqlite3_stmt *p;
+  int rc;
+  i64 nRow = 0;
+
+  zSql = sqlite3_mprintf(zFmt, pRtree->zDb, pRtree->zName);
+  if( zSql==0 ){
+    rc = SQLITE_NOMEM;
+  }else{
+    rc = sqlite3_prepare_v2(db, zSql, -1, &p, 0);
+    if( rc==SQLITE_OK ){
+      if( sqlite3_step(p)==SQLITE_ROW ) nRow = sqlite3_column_int64(p, 0);
+      rc = sqlite3_finalize(p);
+    }else if( rc!=SQLITE_NOMEM ){
+      rc = SQLITE_OK;
+    }
+
+    if( rc==SQLITE_OK ){
+      if( nRow==0 ){
+        pRtree->nRowEst = RTREE_DEFAULT_ROWEST;
+      }else{
+        pRtree->nRowEst = MAX(nRow, RTREE_MIN_ROWEST);
+      }
+    }
+    sqlite3_free(zSql);
+  }
+
+  return rc;
+}
+
 static sqlite3_module rtreeModule = {
   0,                          /* iVersion */
   rtreeCreate,                /* xCreate - create a table */
@@ -2972,7 +3029,8 @@ static int rtreeSqlInit(
     char *zCreate = sqlite3_mprintf(
 "CREATE TABLE \"%w\".\"%w_node\"(nodeno INTEGER PRIMARY KEY, data BLOB);"
 "CREATE TABLE \"%w\".\"%w_rowid\"(rowid INTEGER PRIMARY KEY, nodeno INTEGER);"
-"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY, parentnode INTEGER);"
+"CREATE TABLE \"%w\".\"%w_parent\"(nodeno INTEGER PRIMARY KEY,"
+                                  " parentnode INTEGER);"
 "INSERT INTO '%q'.'%q_node' VALUES(1, zeroblob(%d))",
       zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, zDb, zPrefix, pRtree->iNodeSize
     );
@@ -2996,6 +3054,7 @@ static int rtreeSqlInit(
   appStmt[7] = &pRtree->pWriteParent;
   appStmt[8] = &pRtree->pDeleteParent;
 
+  rc = rtreeQueryStat1(db, pRtree);
   for(i=0; i<N_STATEMENT && rc==SQLITE_OK; i++){
     char *zSql = sqlite3_mprintf(azSql[i], zDb, zPrefix);
     if( zSql ){
@@ -3173,6 +3232,8 @@ static int rtreeInit(
   if( rc==SQLITE_OK ){
     *ppVtab = (sqlite3_vtab *)pRtree;
   }else{
+    assert( *ppVtab==0 );
+    assert( pRtree->nBusy==1 );
     rtreeRelease(pRtree);
   }
   return rc;
@@ -3183,10 +3244,10 @@ static int rtreeInit(
 ** Implementation of a scalar function that decodes r-tree nodes to
 ** human readable strings. This can be used for debugging and analysis.
 **
-** The scalar function takes two arguments, a blob of data containing
-** an r-tree node, and the number of dimensions the r-tree indexes.
-** For a two-dimensional r-tree structure called "rt", to deserialize
-** all nodes, a statement like:
+** The scalar function takes two arguments: (1) the number of dimensions
+** to the rtree (between 1 and 5, inclusive) and (2) a blob of data containing
+** an r-tree node.  For a two-dimensional r-tree structure called "rt", to
+** deserialize all nodes, a statement like:
 **
 **   SELECT rtreenode(2, data) FROM rt_node;
 **
@@ -3219,7 +3280,7 @@ static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
     nCell = (int)strlen(zCell);
     for(jj=0; jj<tree.nDim*2; jj++){
 #ifndef SQLITE_RTREE_INT_ONLY
-      sqlite3_snprintf(512-nCell,&zCell[nCell], " %f",
+      sqlite3_snprintf(512-nCell,&zCell[nCell], " %g",
                        (double)cell.aCoord[jj].f);
 #else
       sqlite3_snprintf(512-nCell,&zCell[nCell], " %d",
@@ -3240,6 +3301,15 @@ static void rtreenode(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
   sqlite3_result_text(ctx, zText, -1, sqlite3_free);
 }
 
+/* This routine implements an SQL function that returns the "depth" parameter
+** from the front of a blob that is an r-tree node.  For example:
+**
+**     SELECT rtreedepth(data) FROM rt_node WHERE nodeno=1;
+**
+** The depth value is 0 for all nodes other than the root node, and the root
+** node always has nodeno=1, so the example above is the primary use for this
+** routine.  This routine is intended for testing and analysis only.
+*/
 static void rtreedepth(sqlite3_context *ctx, int nArg, sqlite3_value **apArg){
   UNUSED_PARAMETER(nArg);
   if( sqlite3_value_type(apArg[0])!=SQLITE_BLOB 
@@ -3282,22 +3352,31 @@ int sqlite3RtreeInit(sqlite3 *db){
 }
 
 /*
-** A version of sqlite3_free() that can be used as a callback. This is used
-** in two places - as the destructor for the blob value returned by the
-** invocation of a geometry function, and as the destructor for the geometry
-** functions themselves.
+** This routine deletes the RtreeGeomCallback object that was attached
+** one of the SQL functions create by sqlite3_rtree_geometry_callback()
+** or sqlite3_rtree_query_callback().  In other words, this routine is the
+** destructor for an RtreeGeomCallback objecct.  This routine is called when
+** the corresponding SQL function is deleted.
 */
-static void doSqlite3Free(void *p){
+static void rtreeFreeCallback(void *p){
+  RtreeGeomCallback *pInfo = (RtreeGeomCallback*)p;
+  if( pInfo->xDestructor ) pInfo->xDestructor(pInfo->pContext);
   sqlite3_free(p);
 }
 
 /*
-** Each call to sqlite3_rtree_geometry_callback() creates an ordinary SQLite
-** scalar user function. This C function is the callback used for all such
-** registered SQL functions.
+** Each call to sqlite3_rtree_geometry_callback() or
+** sqlite3_rtree_query_callback() creates an ordinary SQLite
+** scalar function that is implemented by this routine.
+**
+** All this function does is construct an RtreeMatchArg object that
+** contains the geometry-checking callback routines and a list of
+** parameters to this function, then return that RtreeMatchArg object
+** as a BLOB.
 **
-** The scalar user functions return a blob that is interpreted by r-tree
-** table MATCH operators.
+** The R-Tree MATCH operator will read the returned BLOB, deserialize
+** the RtreeMatchArg object, and use the RtreeMatchArg object to figure
+** out which elements of the R-Tree should be returned by the query.
 */
 static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
   RtreeGeomCallback *pGeomCtx = (RtreeGeomCallback *)sqlite3_user_data(ctx);
@@ -3311,8 +3390,7 @@ static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
   }else{
     int i;
     pBlob->magic = RTREE_GEOMETRY_MAGIC;
-    pBlob->xGeom = pGeomCtx->xGeom;
-    pBlob->pContext = pGeomCtx->pContext;
+    pBlob->cb = pGeomCtx[0];
     pBlob->nParam = nArg;
     for(i=0; i<nArg; i++){
 #ifdef SQLITE_RTREE_INT_ONLY
@@ -3321,7 +3399,7 @@ static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
       pBlob->aParam[i] = sqlite3_value_double(aArg[i]);
 #endif
     }
-    sqlite3_result_blob(ctx, pBlob, nBlob, doSqlite3Free);
+    sqlite3_result_blob(ctx, pBlob, nBlob, sqlite3_free);
   }
 }
 
@@ -3329,10 +3407,10 @@ static void geomCallback(sqlite3_context *ctx, int nArg, sqlite3_value **aArg){
 ** Register a new geometry function for use with the r-tree MATCH operator.
 */
 int sqlite3_rtree_geometry_callback(
-  sqlite3 *db,
-  const char *zGeom,
-  int (*xGeom)(sqlite3_rtree_geometry *, int, RtreeDValue *, int *),
-  void *pContext
+  sqlite3 *db,                  /* Register SQL function on this connection */
+  const char *zGeom,            /* Name of the new SQL function */
+  int (*xGeom)(sqlite3_rtree_geometry*,int,RtreeDValue*,int*), /* Callback */
+  void *pContext                /* Extra data associated with the callback */
 ){
   RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
 
@@ -3340,17 +3418,44 @@ int sqlite3_rtree_geometry_callback(
   pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
   if( !pGeomCtx ) return SQLITE_NOMEM;
   pGeomCtx->xGeom = xGeom;
+  pGeomCtx->xQueryFunc = 0;
+  pGeomCtx->xDestructor = 0;
   pGeomCtx->pContext = pContext;
-
-  /* Create the new user-function. Register a destructor function to delete
-  ** the context object when it is no longer required.  */
   return sqlite3_create_function_v2(db, zGeom, -1, SQLITE_ANY, 
-      (void *)pGeomCtx, geomCallback, 0, 0, doSqlite3Free
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
+  );
+}
+
+/*
+** Register a new 2nd-generation geometry function for use with the
+** r-tree MATCH operator.
+*/
+int sqlite3_rtree_query_callback(
+  sqlite3 *db,                 /* Register SQL function on this connection */
+  const char *zQueryFunc,      /* Name of new SQL function */
+  int (*xQueryFunc)(sqlite3_rtree_query_info*), /* Callback */
+  void *pContext,              /* Extra data passed into the callback */
+  void (*xDestructor)(void*)   /* Destructor for the extra data */
+){
+  RtreeGeomCallback *pGeomCtx;      /* Context object for new user-function */
+
+  /* Allocate and populate the context object. */
+  pGeomCtx = (RtreeGeomCallback *)sqlite3_malloc(sizeof(RtreeGeomCallback));
+  if( !pGeomCtx ) return SQLITE_NOMEM;
+  pGeomCtx->xGeom = 0;
+  pGeomCtx->xQueryFunc = xQueryFunc;
+  pGeomCtx->xDestructor = xDestructor;
+  pGeomCtx->pContext = pContext;
+  return sqlite3_create_function_v2(db, zQueryFunc, -1, SQLITE_ANY, 
+      (void *)pGeomCtx, geomCallback, 0, 0, rtreeFreeCallback
   );
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_rtree_init(
   sqlite3 *db,
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/ext/rtree/rtree1.test b/ext/rtree/rtree1.test
index 275b132..0beb16c 100644
--- a/ext/rtree/rtree1.test
+++ b/ext/rtree/rtree1.test
@@ -33,6 +33,7 @@ set testprefix rtree1
 #   rtree-8.*: Test constrained scans of r-tree data.
 #
 #   rtree-12.*: Test that on-conflict clauses are supported.
+#   rtree-13.*: Test that bug [d2889096e7bdeac6d] has been fixed.
 #
 
 ifcapable !rtree {
@@ -120,12 +121,13 @@ proc execsql_intout {sql} {
 # Test that it is possible to open an existing database that contains
 # r-tree tables.
 #
-do_test rtree-1.4.1 {
-  execsql {
-    CREATE VIRTUAL TABLE t1 USING rtree(ii, x1, x2);
-    INSERT INTO t1 VALUES(1, 5.0, 10.0);
-    INSERT INTO t1 VALUES(2, 15.0, 20.0);
-  }
+do_execsql_test rtree-1.4.1a {
+  CREATE VIRTUAL TABLE t1 USING rtree(ii, x1, x2);
+  INSERT INTO t1 VALUES(1, 5.0, 10.0);
+  SELECT substr(hex(data),1,40) FROM t1_node;
+} {00000001000000000000000140A0000041200000}
+do_execsql_test rtree-1.4.1b {
+  INSERT INTO t1 VALUES(2, 15.0, 20.0);
 } {}
 do_test rtree-1.4.2 {
   db close
@@ -435,16 +437,18 @@ do_test rtree-11.2 {
 # Test on-conflict clause handling.
 #
 db_delete_and_reopen
-do_execsql_test 12.0 {
+do_execsql_test 12.0.1 {
   CREATE VIRTUAL TABLE t1 USING rtree_i32(idx, x1, x2, y1, y2);
   INSERT INTO t1 VALUES(1,   1, 2, 3, 4);
+  SELECT substr(hex(data),1,56) FROM t1_node;
+} {00000001000000000000000100000001000000020000000300000004}
+do_execsql_test 12.0.2 {
   INSERT INTO t1 VALUES(2,   2, 3, 4, 5);
   INSERT INTO t1 VALUES(3,   3, 4, 5, 6);
 
   CREATE TABLE source(idx, x1, x2, y1, y2);
   INSERT INTO source VALUES(5, 8, 8, 8, 8);
   INSERT INTO source VALUES(2, 7, 7, 7, 7);
-  
 }
 db_save_and_close
 foreach {tn sql_template testdata} {
@@ -510,4 +514,25 @@ foreach {tn sql_template testdata} {
     db close
   }
 }
+
+#-------------------------------------------------------------------------
+# Test that bug [d2889096e7bdeac6d] has been fixed.
+#
+reset_db
+do_execsql_test 13.1 {
+  CREATE VIRTUAL TABLE t9 USING rtree(id, xmin, xmax);
+  INSERT INTO t9 VALUES(1,0,0);            
+  INSERT INTO t9 VALUES(2,0,0);
+  SELECT * FROM t9 WHERE id IN (1, 2);
+} {1 0.0 0.0 2 0.0 0.0}
+
+do_execsql_test 13.2 {
+  WITH r(x) AS (
+    SELECT 1 UNION ALL
+    SELECT 2 UNION ALL
+    SELECT 3
+  )
+  SELECT * FROM r CROSS JOIN t9 WHERE id=x;
+} {1 1 0.0 0.0 2 2 0.0 0.0}
+
 finish_test
diff --git a/ext/rtree/rtree6.test b/ext/rtree/rtree6.test
index 92edc8d..cec3a8d 100644
--- a/ext/rtree/rtree6.test
+++ b/ext/rtree/rtree6.test
@@ -57,53 +57,59 @@ do_test rtree6-1.1 {
 
 do_test rtree6-1.2 {
   rtree_strategy {SELECT * FROM t1 WHERE x1>10}
-} {Ea}
+} {E0}
 
 do_test rtree6-1.3 {
   rtree_strategy {SELECT * FROM t1 WHERE x1<10}
-} {Ca}
+} {C0}
 
 do_test rtree6-1.4 {
   rtree_strategy {SELECT * FROM t1,t2 WHERE k=ii AND x1<10}
-} {Ca}
+} {C0}
 
 do_test rtree6-1.5 {
   rtree_strategy {SELECT * FROM t1,t2 WHERE k=+ii AND x1<10}
-} {Ca}
+} {C0}
 
 do_eqp_test rtree6.2.1 {
   SELECT * FROM t1,t2 WHERE k=+ii AND x1<10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_eqp_test rtree6.2.2 {
   SELECT * FROM t1,t2 WHERE k=ii AND x1<10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_eqp_test rtree6.2.3 {
   SELECT * FROM t1,t2 WHERE k=ii
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
-do_eqp_test rtree6.2.4 {
+do_eqp_test rtree6.2.4.1 {
+  SELECT * FROM t1,t2 WHERE v=+ii and x1<10 and x2>10
+} {
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
+  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC COVERING INDEX (v=?)}
+}
+do_eqp_test rtree6.2.4.2 {
   SELECT * FROM t1,t2 WHERE v=10 and x1<10 and x2>10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:CaEb (~0 rows)} 
-  0 1 1 {SCAN TABLE t2 (~100000 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:C0E1} 
+  0 1 1 {SEARCH TABLE t2 USING AUTOMATIC COVERING INDEX (v=?)}
 }
 
 do_eqp_test rtree6.2.5 {
   SELECT * FROM t1,t2 WHERE k=ii AND x1<v
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_execsql_test rtree6-3.1 {
@@ -126,7 +132,7 @@ do_test rtree6.3.2 {
       x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
       x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 
   }
-} {EaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEa}
+} {E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0}
 do_test rtree6.3.3 {
   rtree_strategy {
     SELECT * FROM t3 WHERE 
@@ -137,7 +143,7 @@ do_test rtree6.3.3 {
       x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND 
       x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5 AND x1>0.5
   }
-} {EaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEaEa}
+} {E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0E0}
 
 do_execsql_test rtree6-3.4 {
   SELECT * FROM t3 WHERE x1>0.5 AND x1>0.8 AND x1>1.1
diff --git a/ext/rtree/rtree8.test b/ext/rtree/rtree8.test
index bf22cbf..578a146 100644
--- a/ext/rtree/rtree8.test
+++ b/ext/rtree/rtree8.test
@@ -168,4 +168,3 @@ do_test rtree8-5.3 {
 
 
 finish_test
-
diff --git a/ext/rtree/rtreeB.test b/ext/rtree/rtreeB.test
index 7cb445c..aeb308e 100644
--- a/ext/rtree/rtreeB.test
+++ b/ext/rtree/rtreeB.test
@@ -41,7 +41,7 @@ ifcapable rtree_int_only {
       INSERT INTO t1 VALUES(9223372036854775807, 150, 150, 400, 400);
       SELECT rtreenode(2, data) FROM t1_node;
     }
-  } {{{1073741824 0.000000 0.000000 100.000000 100.000000} {2147483646 0.000000 0.000000 200.000000 200.000000} {4294967296 0.000000 0.000000 300.000000 300.000000} {8589934592 20.000000 20.000000 150.000000 150.000000} {9223372036854775807 150.000000 150.000000 400.000000 400.000000}}}
+  } {{{1073741824 0 0 100 100} {2147483646 0 0 200 200} {4294967296 0 0 300 300} {8589934592 20 20 150 150} {9223372036854775807 150 150 400 400}}}
 }
 
 finish_test
diff --git a/ext/rtree/rtreeC.test b/ext/rtree/rtreeC.test
new file mode 100644
index 0000000..94db05a
--- /dev/null
+++ b/ext/rtree/rtreeC.test
@@ -0,0 +1,273 @@
+# 2011 March 2
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# Make sure the rtreenode() testing function can handle entries with
+# 64-bit rowids.
+# 
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source $testdir/tester.tcl
+ifcapable !rtree { finish_test ; return }
+set testprefix rtreeC
+
+do_execsql_test 1.0 {
+  CREATE VIRTUAL TABLE r_tree USING rtree(id, min_x, max_x, min_y, max_y);
+  CREATE TABLE t(x, y);
+}
+
+do_eqp_test 1.1 {
+  SELECT * FROM r_tree, t 
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND t.x<=max_y
+} {
+  0 0 1 {SCAN TABLE t}
+  0 1 0 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 1.2 {
+  SELECT * FROM t, r_tree
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND t.x<=max_y
+} {
+  0 0 0 {SCAN TABLE t}
+  0 1 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 1.3 {
+  SELECT * FROM t, r_tree
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND ?<=max_y
+} {
+  0 0 0 {SCAN TABLE t}
+  0 1 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 1.5 {
+  SELECT * FROM t, r_tree
+} {
+  0 0 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:}
+  0 1 0 {SCAN TABLE t} 
+}
+
+do_execsql_test 2.0 {
+  INSERT INTO t VALUES(0, 0);
+  INSERT INTO t VALUES(0, 1);
+  INSERT INTO t VALUES(0, 2);
+  INSERT INTO t VALUES(0, 3);
+  INSERT INTO t VALUES(0, 4);
+  INSERT INTO t VALUES(0, 5);
+  INSERT INTO t VALUES(0, 6);
+  INSERT INTO t VALUES(0, 7);
+  INSERT INTO t VALUES(0, 8);
+  INSERT INTO t VALUES(0, 9);
+
+  INSERT INTO t SELECT x+1, y FROM t;
+  INSERT INTO t SELECT x+2, y FROM t;
+  INSERT INTO t SELECT x+4, y FROM t;
+  INSERT INTO r_tree SELECT NULL, x-1, x+1, y-1, y+1 FROM t;
+  ANALYZE;
+}
+
+db close
+sqlite3 db test.db
+
+do_eqp_test 2.1 {
+  SELECT * FROM r_tree, t 
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND t.x<=max_y
+} {
+  0 0 1 {SCAN TABLE t}
+  0 1 0 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 2.2 {
+  SELECT * FROM t, r_tree
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND t.x<=max_y
+} {
+  0 0 0 {SCAN TABLE t}
+  0 1 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 2.3 {
+  SELECT * FROM t, r_tree
+  WHERE t.x>=min_x AND t.x<=max_x AND t.y>=min_y AND ?<=max_y
+} {
+  0 0 0 {SCAN TABLE t}
+  0 1 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:D3B2D1B0}
+}
+
+do_eqp_test 2.5 {
+  SELECT * FROM t, r_tree
+} {
+  0 0 1 {SCAN TABLE r_tree VIRTUAL TABLE INDEX 2:}
+  0 1 0 {SCAN TABLE t} 
+}
+
+#-------------------------------------------------------------------------
+# Test that the special CROSS JOIN handling works with rtree tables.
+#
+do_execsql_test 3.1 {
+  CREATE TABLE t1(x);
+  CREATE TABLE t2(y);
+  CREATE VIRTUAL TABLE t3 USING rtree(z, x1,x2, y1,y2);
+}
+
+do_eqp_test 3.2.1 { SELECT * FROM t1 CROSS JOIN t2 } {
+  0 0 0 {SCAN TABLE t1} 
+  0 1 1 {SCAN TABLE t2}
+}
+do_eqp_test 3.2.2 { SELECT * FROM t2 CROSS JOIN t1 } {
+  0 0 0 {SCAN TABLE t2} 0 1 1 {SCAN TABLE t1}
+}
+
+do_eqp_test 3.3.1 { SELECT * FROM t1 CROSS JOIN t3 } {
+  0 0 0 {SCAN TABLE t1}
+  0 1 1 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
+}
+do_eqp_test 3.3.2 { SELECT * FROM t3 CROSS JOIN t1 } {
+  0 0 0 {SCAN TABLE t3 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SCAN TABLE t1}
+}
+
+#--------------------------------------------------------------------
+# Test that LEFT JOINs are not reordered if the right-hand-side is
+# a virtual table.
+#
+reset_db
+do_execsql_test 4.1 {
+  CREATE TABLE t1(a);
+  CREATE VIRTUAL TABLE t2 USING rtree(b, x1,x2);
+
+  INSERT INTO t1 VALUES(1);
+  INSERT INTO t1 VALUES(2);
+
+  INSERT INTO t2 VALUES(1, 0.0, 0.1);
+  INSERT INTO t2 VALUES(3, 0.0, 0.1);
+}
+
+do_execsql_test 4.2 {
+  SELECT a, b FROM t1 LEFT JOIN t2 ON (+a = +b);
+} {1 1 2 {}}
+
+do_execsql_test 4.3 {
+  SELECT b, a FROM t2 LEFT JOIN t1 ON (+a = +b);
+} {1 1 3 {}}
+
+#--------------------------------------------------------------------
+# Test that the sqlite_stat1 data is used correctly.
+#
+reset_db
+do_execsql_test 5.1 {
+  CREATE TABLE t1(x PRIMARY KEY, y);
+  CREATE VIRTUAL TABLE rt USING rtree(id, x1, x2);
+
+  INSERT INTO t1(x) VALUES(1);
+  INSERT INTO t1(x) SELECT x+1 FROM t1;   --   2
+  INSERT INTO t1(x) SELECT x+2 FROM t1;   --   4
+  INSERT INTO t1(x) SELECT x+4 FROM t1;   --   8
+  INSERT INTO t1(x) SELECT x+8 FROM t1;   --  16
+  INSERT INTO t1(x) SELECT x+16 FROM t1;  --  32
+  INSERT INTO t1(x) SELECT x+32 FROM t1;  --  64
+  INSERT INTO t1(x) SELECT x+64 FROM t1;  -- 128
+  INSERT INTO t1(x) SELECT x+128 FROM t1; -- 256
+  INSERT INTO t1(x) SELECT x+256 FROM t1; -- 512
+  INSERT INTO t1(x) SELECT x+512 FROM t1; --1024
+
+  INSERT INTO rt SELECT x, x, x+1 FROM t1 WHERE x<=5;
+}
+
+# First test a query with no ANALYZE data at all. The outer loop is
+# real table "t1".
+#
+do_eqp_test 5.2 {
+  SELECT * FROM t1, rt WHERE x==id;
+} {
+  0 0 0 {SCAN TABLE t1} 
+  0 1 1 {SCAN TABLE rt VIRTUAL TABLE INDEX 1:}
+}
+
+# Now create enough ANALYZE data to tell SQLite that virtual table "rt"
+# contains very few rows. This causes it to move "rt" to the outer loop.
+#
+do_execsql_test 5.3 {
+  ANALYZE;
+  DELETE FROM sqlite_stat1 WHERE tbl='t1';
+}
+db close
+sqlite3 db test.db
+do_eqp_test 5.4 {
+  SELECT * FROM t1, rt WHERE x==id;
+} {
+  0 0 1 {SCAN TABLE rt VIRTUAL TABLE INDEX 2:} 
+  0 1 0 {SEARCH TABLE t1 USING INDEX sqlite_autoindex_t1_1 (x=?)}
+}
+
+# Delete the ANALYZE data. "t1" should be the outer loop again.
+#
+do_execsql_test 5.5 { DROP TABLE sqlite_stat1; }
+db close
+sqlite3 db test.db
+do_eqp_test 5.6 {
+  SELECT * FROM t1, rt WHERE x==id;
+} {
+  0 0 0 {SCAN TABLE t1} 
+  0 1 1 {SCAN TABLE rt VIRTUAL TABLE INDEX 1:}
+}
+
+# This time create and attach a database that contains ANALYZE data for
+# tables of the same names as those used internally by virtual table
+# "rt". Check that the rtree module is not fooled into using this data.
+# Table "t1" should remain the outer loop.
+#
+do_test 5.7 {
+  db backup test.db2
+  sqlite3 db2 test.db2
+  db2 eval {
+    ANALYZE;
+    DELETE FROM sqlite_stat1 WHERE tbl='t1';
+  }
+  db2 close
+  db close
+  sqlite3 db test.db
+  execsql { ATTACH 'test.db2' AS aux; }
+} {}
+do_eqp_test 5.8 {
+  SELECT * FROM t1, rt WHERE x==id;
+} {
+  0 0 0 {SCAN TABLE t1} 
+  0 1 1 {SCAN TABLE rt VIRTUAL TABLE INDEX 1:}
+}
+
+#--------------------------------------------------------------------
+# Test that having a second connection drop the sqlite_stat1 table
+# before it is required by rtreeConnect() does not cause problems.
+#
+ifcapable rtree {
+  reset_db
+  do_execsql_test 6.1 {
+    CREATE TABLE t1(x);
+    CREATE VIRTUAL TABLE rt USING rtree(id, x1, x2);
+    INSERT INTO t1 VALUES(1);
+    INSERT INTO rt VALUES(1,2,3);
+    ANALYZE;
+  }
+  db close
+  sqlite3 db test.db
+  do_execsql_test 6.2 { SELECT * FROM t1 } {1}
+  
+  do_test 6.3 {
+    sqlite3 db2 test.db
+    db2 eval { DROP TABLE sqlite_stat1 }
+    db2 close
+    execsql { SELECT * FROM rt }
+  } {1 2.0 3.0}
+  db close
+}
+
+
+finish_test
diff --git a/ext/rtree/rtreeD.test b/ext/rtree/rtreeD.test
new file mode 100644
index 0000000..c4a7d22
--- /dev/null
+++ b/ext/rtree/rtreeD.test
@@ -0,0 +1,57 @@
+# 2014 March 11
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# Miscellaneous tests for errors in the rtree constructor.
+#
+
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source [file join [file dirname [info script]] rtree_util.tcl]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+ifcapable !rtree {
+  finish_test
+  return
+}
+set testprefix rtreeD
+
+#-------------------------------------------------------------------------
+# Test that if an SQLITE_BUSY is encountered within the vtable 
+# constructor, a relevant error message is returned.
+#
+do_multiclient_test tn {
+  do_test 1.$tn.1 {
+    sql1 {
+      CREATE TABLE t1(a, b);
+      INSERT INTO t1 VALUES(1,2);
+      CREATE VIRTUAL TABLE rt USING rtree(id, minx, maxx, miny, maxy);
+      INSERT INTO rt VALUES(1,2,3,4,5);
+    }
+  } {}
+
+  do_test 1.$tn.2 {
+    sql2 { SELECT * FROM t1; }
+  } {1 2}
+
+  do_test 1.$tn.3 {
+    sql1 { BEGIN EXCLUSIVE; INSERT INTO t1 VALUES(3, 4); }
+  } {}
+
+  do_test 1.$tn.4 {
+    list [catch { sql2 { SELECT * FROM rt } } msg] $msg
+  } {1 {database is locked}}
+}
+
+finish_test
+
+
diff --git a/ext/rtree/rtreeE.test b/ext/rtree/rtreeE.test
new file mode 100644
index 0000000..c450623
--- /dev/null
+++ b/ext/rtree/rtreeE.test
@@ -0,0 +1,129 @@
+# 2010 August 28
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file contains tests for the r-tree module. Specifically, it tests
+# that new-style custom r-tree queries (geometry callbacks) work.
+# 
+
+if {![info exists testdir]} {
+  set testdir [file join [file dirname [info script]] .. .. test]
+} 
+source $testdir/tester.tcl
+ifcapable !rtree { finish_test ; return }
+ifcapable rtree_int_only { finish_test; return }
+
+
+#-------------------------------------------------------------------------
+# Test the example 2d "circle" geometry callback.
+#
+register_circle_geom db
+
+do_execsql_test rtreeE-1.1 {
+  PRAGMA page_size=512;
+  CREATE VIRTUAL TABLE rt1 USING rtree(id,x0,x1,y0,y1);
+  
+  /* A tight pattern of small boxes near 0,0 */
+  WITH RECURSIVE
+    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
+    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
+  INSERT INTO rt1 SELECT x+5*y, x, x+2, y, y+2 FROM x, y;
+
+  /* A looser pattern of small boxes near 100, 0 */
+  WITH RECURSIVE
+    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
+    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
+  INSERT INTO rt1 SELECT 100+x+5*y, x*3+100, x*3+102, y*3, y*3+2 FROM x, y;
+
+  /* A looser pattern of larger boxes near 0, 200 */
+  WITH RECURSIVE
+    x(x) AS (VALUES(0) UNION ALL SELECT x+1 FROM x WHERE x<4),
+    y(y) AS (VALUES(0) UNION ALL SELECT y+1 FROM y WHERE y<4)
+  INSERT INTO rt1 SELECT 200+x+5*y, x*7, x*7+15, y*7+200, y*7+215 FROM x, y;
+} {}
+
+# Queries against each of the three clusters */
+do_execsql_test rtreeE-1.1 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(0.0, 0.0, 50.0, 3) ORDER BY id;
+} {0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24}
+do_execsql_test rtreeE-1.2 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(100.0, 0.0, 50.0, 3) ORDER BY id;
+} {100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124}
+do_execsql_test rtreeE-1.3 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(0.0, 200.0, 50.0, 3) ORDER BY id;
+} {200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224}
+
+# The Qcircle geometry function gives a lower score to larger leaf-nodes.
+# This causes the 200s to sort before the 100s and the 0s to sort before
+# last.
+#
+do_execsql_test rtreeE-1.4 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(0,0,1000,3) AND id%100==0
+} {200 100 0}
+
+# Exclude odd rowids on a depth-first search
+do_execsql_test rtreeE-1.5 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(0,0,1000,4) ORDER BY +id
+} {0 2 4 6 8 10 12 14 16 18 20 22 24 100 102 104 106 108 110 112 114 116 118 120 122 124 200 202 204 206 208 210 212 214 216 218 220 222 224}
+
+# Exclude odd rowids on a breadth-first search.
+do_execsql_test rtreeE-1.6 {
+  SELECT id FROM rt1 WHERE id MATCH Qcircle(0,0,1000,5) ORDER BY +id
+} {0 2 4 6 8 10 12 14 16 18 20 22 24 100 102 104 106 108 110 112 114 116 118 120 122 124 200 202 204 206 208 210 212 214 216 218 220 222 224}
+
+# Construct a large 2-D RTree with thousands of random entries.
+#
+do_test rtreeE-2.1 {
+  db eval {
+    CREATE TABLE t2(id,x0,x1,y0,y1);
+    CREATE VIRTUAL TABLE rt2 USING rtree(id,x0,x1,y0,y1);
+    BEGIN;
+  }
+  expr srand(0)
+  for {set i 1} {$i<=10000} {incr i} {
+    set dx [expr {int(rand()*40)+1}]
+    set dy [expr {int(rand()*40)+1}]
+    set x0 [expr {int(rand()*(10000 - $dx))}]
+    set x1 [expr {$x0+$dx}]
+    set y0 [expr {int(rand()*(10000 - $dy))}]
+    set y1 [expr {$y0+$dy}]
+    set id [expr {$i+10000}]
+    db eval {INSERT INTO t2 VALUES($id,$x0,$x1,$y0,$y1)}
+  }
+  db eval {
+    INSERT INTO rt2 SELECT * FROM t2;
+    COMMIT;
+  }
+} {}
+
+for {set i 1} {$i<=200} {incr i} {
+  set dx [expr {int(rand()*100)}]
+  set dy [expr {int(rand()*100)}]
+  set x0 [expr {int(rand()*(10000 - $dx))}]
+  set x1 [expr {$x0+$dx}]
+  set y0 [expr {int(rand()*(10000 - $dy))}]
+  set y1 [expr {$y0+$dy}]
+  set ans [db eval {SELECT id FROM t2 WHERE x1>=$x0 AND x0<=$x1 AND y1>=$y0 AND y0<=$y1 ORDER BY id}]
+  do_execsql_test rtreeE-2.2.$i {
+    SELECT id FROM rt2 WHERE id MATCH breadthfirstsearch($x0,$x1,$y0,$y1) ORDER BY id
+  } $ans
+}
+
+# Run query that have very deep priority queues
+#
+set ans [db eval {SELECT id FROM t2 WHERE x1>=0 AND x0<=5000 AND y1>=0 AND y0<=5000 ORDER BY id}]
+do_execsql_test rtreeE-2.3 {
+  SELECT id FROM rt2 WHERE id MATCH breadthfirstsearch(0,5000,0,5000) ORDER BY id
+} $ans
+set ans [db eval {SELECT id FROM t2 WHERE x1>=0 AND x0<=10000 AND y1>=0 AND y0<=10000 ORDER BY id}]
+do_execsql_test rtreeE-2.4 {
+  SELECT id FROM rt2 WHERE id MATCH breadthfirstsearch(0,10000,0,10000) ORDER BY id
+} $ans
+
+finish_test
diff --git a/ext/rtree/sqlite3rtree.h b/ext/rtree/sqlite3rtree.h
index c849091..5de0508 100644
--- a/ext/rtree/sqlite3rtree.h
+++ b/ext/rtree/sqlite3rtree.h
@@ -21,6 +21,16 @@ extern "C" {
 #endif
 
 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
+typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
+
+/* The double-precision datatype used by RTree depends on the
+** SQLITE_RTREE_INT_ONLY compile-time option.
+*/
+#ifdef SQLITE_RTREE_INT_ONLY
+  typedef sqlite3_int64 sqlite3_rtree_dbl;
+#else
+  typedef double sqlite3_rtree_dbl;
+#endif
 
 /*
 ** Register a geometry callback named zGeom that can be used as part of an
@@ -31,11 +41,7 @@ typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
 int sqlite3_rtree_geometry_callback(
   sqlite3 *db,
   const char *zGeom,
-#ifdef SQLITE_RTREE_INT_ONLY
-  int (*xGeom)(sqlite3_rtree_geometry*, int n, sqlite3_int64 *a, int *pRes),
-#else
-  int (*xGeom)(sqlite3_rtree_geometry*, int n, double *a, int *pRes),
-#endif
+  int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
   void *pContext
 );
 
@@ -47,11 +53,60 @@ int sqlite3_rtree_geometry_callback(
 struct sqlite3_rtree_geometry {
   void *pContext;                 /* Copy of pContext passed to s_r_g_c() */
   int nParam;                     /* Size of array aParam[] */
-  double *aParam;                 /* Parameters passed to SQL geom function */
+  sqlite3_rtree_dbl *aParam;      /* Parameters passed to SQL geom function */
   void *pUser;                    /* Callback implementation user data */
   void (*xDelUser)(void *);       /* Called by SQLite to clean up pUser */
 };
 
+/*
+** Register a 2nd-generation geometry callback named zScore that can be 
+** used as part of an R-Tree geometry query as follows:
+**
+**   SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
+*/
+int sqlite3_rtree_query_callback(
+  sqlite3 *db,
+  const char *zQueryFunc,
+  int (*xQueryFunc)(sqlite3_rtree_query_info*),
+  void *pContext,
+  void (*xDestructor)(void*)
+);
+
+
+/*
+** A pointer to a structure of the following type is passed as the 
+** argument to scored geometry callback registered using
+** sqlite3_rtree_query_callback().
+**
+** Note that the first 5 fields of this structure are identical to
+** sqlite3_rtree_geometry.  This structure is a subclass of
+** sqlite3_rtree_geometry.
+*/
+struct sqlite3_rtree_query_info {
+  void *pContext;                   /* pContext from when function registered */
+  int nParam;                       /* Number of function parameters */
+  sqlite3_rtree_dbl *aParam;        /* value of function parameters */
+  void *pUser;                      /* callback can use this, if desired */
+  void (*xDelUser)(void*);          /* function to free pUser */
+  sqlite3_rtree_dbl *aCoord;        /* Coordinates of node or entry to check */
+  unsigned int *anQueue;            /* Number of pending entries in the queue */
+  int nCoord;                       /* Number of coordinates */
+  int iLevel;                       /* Level of current node or entry */
+  int mxLevel;                      /* The largest iLevel value in the tree */
+  sqlite3_int64 iRowid;             /* Rowid for current entry */
+  sqlite3_rtree_dbl rParentScore;   /* Score of parent node */
+  int eParentWithin;                /* Visibility of parent node */
+  int eWithin;                      /* OUT: Visiblity */
+  sqlite3_rtree_dbl rScore;         /* OUT: Write the score here */
+};
+
+/*
+** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
+*/
+#define NOT_WITHIN       0   /* Object completely outside of query region */
+#define PARTLY_WITHIN    1   /* Object partially overlaps query region */
+#define FULLY_WITHIN     2   /* Object fully contained within query region */
+
 
 #ifdef __cplusplus
 }  /* end of the 'extern "C"' block */