diff options
Diffstat (limited to 'src/analyze.c')
| -rw-r--r-- | src/analyze.c | 1788 |
1 files changed, 1258 insertions, 530 deletions
diff --git a/src/analyze.c b/src/analyze.c index 9a3e959..f9c03dc 100644 --- a/src/analyze.c +++ b/src/analyze.c @@ -1,5 +1,5 @@ /* -** 2005 July 8 +** 2005-07-08 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: @@ -20,15 +20,23 @@ ** CREATE TABLE sqlite_stat1(tbl, idx, stat); ** CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample); ** CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample); +** CREATE TABLE sqlite_stat4(tbl, idx, nEq, nLt, nDLt, sample); ** ** Additional tables might be added in future releases of SQLite. ** The sqlite_stat2 table is not created or used unless the SQLite version ** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled ** with SQLITE_ENABLE_STAT2. The sqlite_stat2 table is deprecated. -** The sqlite_stat2 table is superceded by sqlite_stat3, which is only +** The sqlite_stat2 table is superseded by sqlite_stat3, which is only ** created and used by SQLite versions 3.7.9 and later and with -** SQLITE_ENABLE_STAT3 defined. The fucntionality of sqlite_stat3 -** is a superset of sqlite_stat2. +** SQLITE_ENABLE_STAT3 defined. The functionality of sqlite_stat3 +** is a superset of sqlite_stat2. The sqlite_stat4 is an enhanced +** version of sqlite_stat3 and is only available when compiled with +** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.1 and later. It is +** not possible to enable both STAT3 and STAT4 at the same time. If they +** are both enabled, then STAT4 takes precedence. +** +** For most applications, sqlite_stat1 provides all the statisics required +** for the query planner to make good choices. ** ** Format of sqlite_stat1: ** @@ -36,7 +44,8 @@ ** name in the idx column. The tbl column is the name of the table to ** which the index belongs. In each such row, the stat column will be ** a string consisting of a list of integers. The first integer in this -** list is the number of rows in the index and in the table. The second +** list is the number of rows in the index. (This is the same as the +** number of rows in the table, except for partial indices.) The second ** integer is the average number of rows in the index that have the same ** value in the first column of the index. The third integer is the average ** number of rows in the index that have the same value for the first two @@ -83,54 +92,82 @@ ** ** Format for sqlite_stat3: ** -** The sqlite_stat3 is an enhancement to sqlite_stat2. A new name is -** used to avoid compatibility problems. +** The sqlite_stat3 format is a subset of sqlite_stat4. Hence, the +** sqlite_stat4 format will be described first. Further information +** about sqlite_stat3 follows the sqlite_stat4 description. +** +** Format for sqlite_stat4: +** +** As with sqlite_stat2, the sqlite_stat4 table contains histogram data +** to aid the query planner in choosing good indices based on the values +** that indexed columns are compared against in the WHERE clauses of +** queries. ** -** The format of the sqlite_stat3 table is similar to the format of -** the sqlite_stat2 table. There are multiple entries for each index. +** The sqlite_stat4 table contains multiple entries for each index. ** The idx column names the index and the tbl column is the table of the ** index. If the idx and tbl columns are the same, then the sample is -** of the INTEGER PRIMARY KEY. The sample column is a value taken from -** the left-most column of the index. The nEq column is the approximate -** number of entires in the index whose left-most column exactly matches -** the sample. nLt is the approximate number of entires whose left-most -** column is less than the sample. The nDLt column is the approximate -** number of distinct left-most entries in the index that are less than -** the sample. +** of the INTEGER PRIMARY KEY. The sample column is a blob which is the +** binary encoding of a key from the index. The nEq column is a +** list of integers. The first integer is the approximate number +** of entries in the index whose left-most column exactly matches +** the left-most column of the sample. The second integer in nEq +** is the approximate number of entries in the index where the +** first two columns match the first two columns of the sample. +** And so forth. nLt is another list of integers that show the approximate +** number of entries that are strictly less than the sample. The first +** integer in nLt contains the number of entries in the index where the +** left-most column is less than the left-most column of the sample. +** The K-th integer in the nLt entry is the number of index entries +** where the first K columns are less than the first K columns of the +** sample. The nDLt column is like nLt except that it contains the +** number of distinct entries in the index that are less than the +** sample. ** -** Future versions of SQLite might change to store a string containing -** multiple integers values in the nDLt column of sqlite_stat3. The first -** integer will be the number of prior index entires that are distinct in -** the left-most column. The second integer will be the number of prior index -** entries that are distinct in the first two columns. The third integer -** will be the number of prior index entries that are distinct in the first -** three columns. And so forth. With that extension, the nDLt field is -** similar in function to the sqlite_stat1.stat field. -** -** There can be an arbitrary number of sqlite_stat3 entries per index. -** The ANALYZE command will typically generate sqlite_stat3 tables +** There can be an arbitrary number of sqlite_stat4 entries per index. +** The ANALYZE command will typically generate sqlite_stat4 tables ** that contain between 10 and 40 samples which are distributed across ** the key space, though not uniformly, and which include samples with -** largest possible nEq values. +** large nEq values. +** +** Format for sqlite_stat3 redux: +** +** The sqlite_stat3 table is like sqlite_stat4 except that it only +** looks at the left-most column of the index. The sqlite_stat3.sample +** column contains the actual value of the left-most column instead +** of a blob encoding of the complete index key as is found in +** sqlite_stat4.sample. The nEq, nLt, and nDLt entries of sqlite_stat3 +** all contain just a single integer which is the same as the first +** integer in the equivalent columns in sqlite_stat4. */ #ifndef SQLITE_OMIT_ANALYZE #include "sqliteInt.h" +#if defined(SQLITE_ENABLE_STAT4) +# define IsStat4 1 +# define IsStat3 0 +#elif defined(SQLITE_ENABLE_STAT3) +# define IsStat4 0 +# define IsStat3 1 +#else +# define IsStat4 0 +# define IsStat3 0 +# undef SQLITE_STAT4_SAMPLES +# define SQLITE_STAT4_SAMPLES 1 +#endif +#define IsStat34 (IsStat3+IsStat4) /* 1 for STAT3 or STAT4. 0 otherwise */ + /* -** This routine generates code that opens the sqlite_stat1 table for -** writing with cursor iStatCur. If the library was built with the -** SQLITE_ENABLE_STAT3 macro defined, then the sqlite_stat3 table is -** opened for writing using cursor (iStatCur+1) +** This routine generates code that opens the sqlite_statN tables. +** The sqlite_stat1 table is always relevant. sqlite_stat2 is now +** obsolete. sqlite_stat3 and sqlite_stat4 are only opened when +** appropriate compile-time options are provided. ** -** If the sqlite_stat1 tables does not previously exist, it is created. -** Similarly, if the sqlite_stat3 table does not exist and the library -** is compiled with SQLITE_ENABLE_STAT3 defined, it is created. +** If the sqlite_statN tables do not previously exist, it is created. ** ** Argument zWhere may be a pointer to a buffer containing a table name, ** or it may be a NULL pointer. If it is not NULL, then all entries in -** the sqlite_stat1 and (if applicable) sqlite_stat3 tables associated -** with the named table are deleted. If zWhere==0, then code is generated -** to delete all stat table entries. +** the sqlite_statN tables associated with the named table are deleted. +** If zWhere==0, then code is generated to delete all stat table entries. */ static void openStatTable( Parse *pParse, /* Parsing context */ @@ -144,18 +181,24 @@ static void openStatTable( const char *zCols; } aTable[] = { { "sqlite_stat1", "tbl,idx,stat" }, -#ifdef SQLITE_ENABLE_STAT3 +#if defined(SQLITE_ENABLE_STAT4) + { "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" }, + { "sqlite_stat3", 0 }, +#elif defined(SQLITE_ENABLE_STAT3) { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" }, + { "sqlite_stat4", 0 }, +#else + { "sqlite_stat3", 0 }, + { "sqlite_stat4", 0 }, #endif }; - - int aRoot[] = {0, 0}; - u8 aCreateTbl[] = {0, 0}; - int i; sqlite3 *db = pParse->db; Db *pDb; Vdbe *v = sqlite3GetVdbe(pParse); + int aRoot[ArraySize(aTable)]; + u8 aCreateTbl[ArraySize(aTable)]; + if( v==0 ) return; assert( sqlite3BtreeHoldsAllMutexes(db) ); assert( sqlite3VdbeDb(v)==db ); @@ -168,258 +211,738 @@ static void openStatTable( const char *zTab = aTable[i].zName; Table *pStat; if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){ - /* The sqlite_stat[12] table does not exist. Create it. Note that a - ** side-effect of the CREATE TABLE statement is to leave the rootpage - ** of the new table in register pParse->regRoot. This is important - ** because the OpenWrite opcode below will be needing it. */ - sqlite3NestedParse(pParse, - "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols - ); - aRoot[i] = pParse->regRoot; - aCreateTbl[i] = OPFLAG_P2ISREG; + if( aTable[i].zCols ){ + /* The sqlite_statN table does not exist. Create it. Note that a + ** side-effect of the CREATE TABLE statement is to leave the rootpage + ** of the new table in register pParse->regRoot. This is important + ** because the OpenWrite opcode below will be needing it. */ + sqlite3NestedParse(pParse, + "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols + ); + aRoot[i] = pParse->regRoot; + aCreateTbl[i] = OPFLAG_P2ISREG; + } }else{ /* The table already exists. If zWhere is not NULL, delete all entries ** associated with the table zWhere. If zWhere is NULL, delete the ** entire contents of the table. */ aRoot[i] = pStat->tnum; + aCreateTbl[i] = 0; sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab); if( zWhere ){ sqlite3NestedParse(pParse, - "DELETE FROM %Q.%s WHERE %s=%Q", pDb->zName, zTab, zWhereType, zWhere + "DELETE FROM %Q.%s WHERE %s=%Q", + pDb->zName, zTab, zWhereType, zWhere ); }else{ - /* The sqlite_stat[12] table already exists. Delete all rows. */ + /* The sqlite_stat[134] table already exists. Delete all rows. */ sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb); } } } - /* Open the sqlite_stat[13] tables for writing. */ - for(i=0; i<ArraySize(aTable); i++){ - sqlite3VdbeAddOp3(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb); - sqlite3VdbeChangeP4(v, -1, (char *)3, P4_INT32); + /* Open the sqlite_stat[134] tables for writing. */ + for(i=0; aTable[i].zCols; i++){ + assert( i<ArraySize(aTable) ); + sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3); sqlite3VdbeChangeP5(v, aCreateTbl[i]); + VdbeComment((v, aTable[i].zName)); } } /* -** Recommended number of samples for sqlite_stat3 +** Recommended number of samples for sqlite_stat4 */ -#ifndef SQLITE_STAT3_SAMPLES -# define SQLITE_STAT3_SAMPLES 24 +#ifndef SQLITE_STAT4_SAMPLES +# define SQLITE_STAT4_SAMPLES 24 #endif /* -** Three SQL functions - stat3_init(), stat3_push(), and stat3_pop() - +** Three SQL functions - stat_init(), stat_push(), and stat_get() - ** share an instance of the following structure to hold their state ** information. */ -typedef struct Stat3Accum Stat3Accum; -struct Stat3Accum { +typedef struct Stat4Accum Stat4Accum; +typedef struct Stat4Sample Stat4Sample; +struct Stat4Sample { + tRowcnt *anEq; /* sqlite_stat4.nEq */ + tRowcnt *anDLt; /* sqlite_stat4.nDLt */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + tRowcnt *anLt; /* sqlite_stat4.nLt */ + union { + i64 iRowid; /* Rowid in main table of the key */ + u8 *aRowid; /* Key for WITHOUT ROWID tables */ + } u; + u32 nRowid; /* Sizeof aRowid[] */ + u8 isPSample; /* True if a periodic sample */ + int iCol; /* If !isPSample, the reason for inclusion */ + u32 iHash; /* Tiebreaker hash */ +#endif +}; +struct Stat4Accum { tRowcnt nRow; /* Number of rows in the entire table */ tRowcnt nPSample; /* How often to do a periodic sample */ - int iMin; /* Index of entry with minimum nEq and hash */ + int nCol; /* Number of columns in index + pk/rowid */ + int nKeyCol; /* Number of index columns w/o the pk/rowid */ int mxSample; /* Maximum number of samples to accumulate */ - int nSample; /* Current number of samples */ + Stat4Sample current; /* Current row as a Stat4Sample */ u32 iPrn; /* Pseudo-random number used for sampling */ - struct Stat3Sample { - i64 iRowid; /* Rowid in main table of the key */ - tRowcnt nEq; /* sqlite_stat3.nEq */ - tRowcnt nLt; /* sqlite_stat3.nLt */ - tRowcnt nDLt; /* sqlite_stat3.nDLt */ - u8 isPSample; /* True if a periodic sample */ - u32 iHash; /* Tiebreaker hash */ - } *a; /* An array of samples */ + Stat4Sample *aBest; /* Array of nCol best samples */ + int iMin; /* Index in a[] of entry with minimum score */ + int nSample; /* Current number of samples */ + int iGet; /* Index of current sample accessed by stat_get() */ + Stat4Sample *a; /* Array of mxSample Stat4Sample objects */ + sqlite3 *db; /* Database connection, for malloc() */ }; -#ifdef SQLITE_ENABLE_STAT3 +/* Reclaim memory used by a Stat4Sample +*/ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +static void sampleClear(sqlite3 *db, Stat4Sample *p){ + assert( db!=0 ); + if( p->nRowid ){ + sqlite3DbFree(db, p->u.aRowid); + p->nRowid = 0; + } +} +#endif + +/* Initialize the BLOB value of a ROWID +*/ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){ + assert( db!=0 ); + if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid); + p->u.aRowid = sqlite3DbMallocRaw(db, n); + if( p->u.aRowid ){ + p->nRowid = n; + memcpy(p->u.aRowid, pData, n); + }else{ + p->nRowid = 0; + } +} +#endif + +/* Initialize the INTEGER value of a ROWID. +*/ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +static void sampleSetRowidInt64(sqlite3 *db, Stat4Sample *p, i64 iRowid){ + assert( db!=0 ); + if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid); + p->nRowid = 0; + p->u.iRowid = iRowid; +} +#endif + + /* -** Implementation of the stat3_init(C,S) SQL function. The two parameters -** are the number of rows in the table or index (C) and the number of samples -** to accumulate (S). +** Copy the contents of object (*pFrom) into (*pTo). +*/ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +static void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){ + pTo->isPSample = pFrom->isPSample; + pTo->iCol = pFrom->iCol; + pTo->iHash = pFrom->iHash; + memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol); + memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol); + memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol); + if( pFrom->nRowid ){ + sampleSetRowid(p->db, pTo, pFrom->nRowid, pFrom->u.aRowid); + }else{ + sampleSetRowidInt64(p->db, pTo, pFrom->u.iRowid); + } +} +#endif + +/* +** Reclaim all memory of a Stat4Accum structure. +*/ +static void stat4Destructor(void *pOld){ + Stat4Accum *p = (Stat4Accum*)pOld; +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + int i; + for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i); + for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i); + sampleClear(p->db, &p->current); +#endif + sqlite3DbFree(p->db, p); +} + +/* +** Implementation of the stat_init(N,K,C) SQL function. The three parameters +** are: +** N: The number of columns in the index including the rowid/pk (note 1) +** K: The number of columns in the index excluding the rowid/pk. +** C: The number of rows in the index (note 2) +** +** Note 1: In the special case of the covering index that implements a +** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the +** total number of columns in the table. +** +** Note 2: C is only used for STAT3 and STAT4. ** -** This routine allocates the Stat3Accum object. +** For indexes on ordinary rowid tables, N==K+1. But for indexes on +** WITHOUT ROWID tables, N=K+P where P is the number of columns in the +** PRIMARY KEY of the table. The covering index that implements the +** original WITHOUT ROWID table as N==K as a special case. ** -** The return value is the Stat3Accum object (P). +** This routine allocates the Stat4Accum object in heap memory. The return +** value is a pointer to the the Stat4Accum object encoded as a blob (i.e. +** the size of the blob is sizeof(void*) bytes). */ -static void stat3Init( +static void statInit( sqlite3_context *context, int argc, sqlite3_value **argv ){ - Stat3Accum *p; - tRowcnt nRow; - int mxSample; - int n; + Stat4Accum *p; + int nCol; /* Number of columns in index being sampled */ + int nKeyCol; /* Number of key columns */ + int nColUp; /* nCol rounded up for alignment */ + int n; /* Bytes of space to allocate */ + sqlite3 *db; /* Database connection */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + int mxSample = SQLITE_STAT4_SAMPLES; +#endif + /* Decode the three function arguments */ UNUSED_PARAMETER(argc); - nRow = (tRowcnt)sqlite3_value_int64(argv[0]); - mxSample = sqlite3_value_int(argv[1]); - n = sizeof(*p) + sizeof(p->a[0])*mxSample; - p = sqlite3MallocZero( n ); + nCol = sqlite3_value_int(argv[0]); + assert( nCol>0 ); + nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol; + nKeyCol = sqlite3_value_int(argv[1]); + assert( nKeyCol<=nCol ); + assert( nKeyCol>0 ); + + /* Allocate the space required for the Stat4Accum object */ + n = sizeof(*p) + + sizeof(tRowcnt)*nColUp /* Stat4Accum.anEq */ + + sizeof(tRowcnt)*nColUp /* Stat4Accum.anDLt */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + + sizeof(tRowcnt)*nColUp /* Stat4Accum.anLt */ + + sizeof(Stat4Sample)*(nCol+mxSample) /* Stat4Accum.aBest[], a[] */ + + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample) +#endif + ; + db = sqlite3_context_db_handle(context); + p = sqlite3DbMallocZero(db, n); if( p==0 ){ sqlite3_result_error_nomem(context); return; } - p->a = (struct Stat3Sample*)&p[1]; - p->nRow = nRow; - p->mxSample = mxSample; - p->nPSample = p->nRow/(mxSample/3+1) + 1; - sqlite3_randomness(sizeof(p->iPrn), &p->iPrn); - sqlite3_result_blob(context, p, sizeof(p), sqlite3_free); + + p->db = db; + p->nRow = 0; + p->nCol = nCol; + p->nKeyCol = nKeyCol; + p->current.anDLt = (tRowcnt*)&p[1]; + p->current.anEq = &p->current.anDLt[nColUp]; + +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + { + u8 *pSpace; /* Allocated space not yet assigned */ + int i; /* Used to iterate through p->aSample[] */ + + p->iGet = -1; + p->mxSample = mxSample; + p->nPSample = (tRowcnt)(sqlite3_value_int64(argv[2])/(mxSample/3+1) + 1); + p->current.anLt = &p->current.anEq[nColUp]; + p->iPrn = nCol*0x689e962d ^ sqlite3_value_int(argv[2])*0xd0944565; + + /* Set up the Stat4Accum.a[] and aBest[] arrays */ + p->a = (struct Stat4Sample*)&p->current.anLt[nColUp]; + p->aBest = &p->a[mxSample]; + pSpace = (u8*)(&p->a[mxSample+nCol]); + for(i=0; i<(mxSample+nCol); i++){ + p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); + p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); + p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); + } + assert( (pSpace - (u8*)p)==n ); + + for(i=0; i<nCol; i++){ + p->aBest[i].iCol = i; + } + } +#endif + + /* Return a pointer to the allocated object to the caller */ + sqlite3_result_blob(context, p, sizeof(p), stat4Destructor); } -static const FuncDef stat3InitFuncdef = { - 2, /* nArg */ - SQLITE_UTF8, /* iPrefEnc */ - 0, /* flags */ - 0, /* pUserData */ - 0, /* pNext */ - stat3Init, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat3_init", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ +static const FuncDef statInitFuncdef = { + 2+IsStat34, /* nArg */ + SQLITE_UTF8, /* funcFlags */ + 0, /* pUserData */ + 0, /* pNext */ + statInit, /* xFunc */ + 0, /* xStep */ + 0, /* xFinalize */ + "stat_init", /* zName */ + 0, /* pHash */ + 0 /* pDestructor */ }; +#ifdef SQLITE_ENABLE_STAT4 +/* +** pNew and pOld are both candidate non-periodic samples selected for +** the same column (pNew->iCol==pOld->iCol). Ignoring this column and +** considering only any trailing columns and the sample hash value, this +** function returns true if sample pNew is to be preferred over pOld. +** In other words, if we assume that the cardinalities of the selected +** column for pNew and pOld are equal, is pNew to be preferred over pOld. +** +** This function assumes that for each argument sample, the contents of +** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. +*/ +static int sampleIsBetterPost( + Stat4Accum *pAccum, + Stat4Sample *pNew, + Stat4Sample *pOld +){ + int nCol = pAccum->nCol; + int i; + assert( pNew->iCol==pOld->iCol ); + for(i=pNew->iCol+1; i<nCol; i++){ + if( pNew->anEq[i]>pOld->anEq[i] ) return 1; + if( pNew->anEq[i]<pOld->anEq[i] ) return 0; + } + if( pNew->iHash>pOld->iHash ) return 1; + return 0; +} +#endif + +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +/* +** Return true if pNew is to be preferred over pOld. +** +** This function assumes that for each argument sample, the contents of +** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. +*/ +static int sampleIsBetter( + Stat4Accum *pAccum, + Stat4Sample *pNew, + Stat4Sample *pOld +){ + tRowcnt nEqNew = pNew->anEq[pNew->iCol]; + tRowcnt nEqOld = pOld->anEq[pOld->iCol]; + + assert( pOld->isPSample==0 && pNew->isPSample==0 ); + assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) ); + + if( (nEqNew>nEqOld) ) return 1; +#ifdef SQLITE_ENABLE_STAT4 + if( nEqNew==nEqOld ){ + if( pNew->iCol<pOld->iCol ) return 1; + return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld)); + } + return 0; +#else + return (nEqNew==nEqOld && pNew->iHash>pOld->iHash); +#endif +} + +/* +** Copy the contents of sample *pNew into the p->a[] array. If necessary, +** remove the least desirable sample from p->a[] to make room. +*/ +static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){ + Stat4Sample *pSample = 0; + int i; + + assert( IsStat4 || nEqZero==0 ); + +#ifdef SQLITE_ENABLE_STAT4 + if( pNew->isPSample==0 ){ + Stat4Sample *pUpgrade = 0; + assert( pNew->anEq[pNew->iCol]>0 ); + + /* This sample is being added because the prefix that ends in column + ** iCol occurs many times in the table. However, if we have already + ** added a sample that shares this prefix, there is no need to add + ** this one. Instead, upgrade the priority of the highest priority + ** existing sample that shares this prefix. */ + for(i=p->nSample-1; i>=0; i--){ + Stat4Sample *pOld = &p->a[i]; + if( pOld->anEq[pNew->iCol]==0 ){ + if( pOld->isPSample ) return; + assert( pOld->iCol>pNew->iCol ); + assert( sampleIsBetter(p, pNew, pOld) ); + if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){ + pUpgrade = pOld; + } + } + } + if( pUpgrade ){ + pUpgrade->iCol = pNew->iCol; + pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol]; + goto find_new_min; + } + } +#endif + + /* If necessary, remove sample iMin to make room for the new sample. */ + if( p->nSample>=p->mxSample ){ + Stat4Sample *pMin = &p->a[p->iMin]; + tRowcnt *anEq = pMin->anEq; + tRowcnt *anLt = pMin->anLt; + tRowcnt *anDLt = pMin->anDLt; + sampleClear(p->db, pMin); + memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1)); + pSample = &p->a[p->nSample-1]; + pSample->nRowid = 0; + pSample->anEq = anEq; + pSample->anDLt = anDLt; + pSample->anLt = anLt; + p->nSample = p->mxSample-1; + } + + /* The "rows less-than" for the rowid column must be greater than that + ** for the last sample in the p->a[] array. Otherwise, the samples would + ** be out of order. */ +#ifdef SQLITE_ENABLE_STAT4 + assert( p->nSample==0 + || pNew->anLt[p->nCol-1] > p->a[p->nSample-1].anLt[p->nCol-1] ); +#endif + + /* Insert the new sample */ + pSample = &p->a[p->nSample]; + sampleCopy(p, pSample, pNew); + p->nSample++; + + /* Zero the first nEqZero entries in the anEq[] array. */ + memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero); + +#ifdef SQLITE_ENABLE_STAT4 + find_new_min: +#endif + if( p->nSample>=p->mxSample ){ + int iMin = -1; + for(i=0; i<p->mxSample; i++){ + if( p->a[i].isPSample ) continue; + if( iMin<0 || sampleIsBetter(p, &p->a[iMin], &p->a[i]) ){ + iMin = i; + } + } + assert( iMin>=0 ); + p->iMin = iMin; + } +} +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ + +/* +** Field iChng of the index being scanned has changed. So at this point +** p->current contains a sample that reflects the previous row of the +** index. The value of anEq[iChng] and subsequent anEq[] elements are +** correct at this point. +*/ +static void samplePushPrevious(Stat4Accum *p, int iChng){ +#ifdef SQLITE_ENABLE_STAT4 + int i; + + /* Check if any samples from the aBest[] array should be pushed + ** into IndexSample.a[] at this point. */ + for(i=(p->nCol-2); i>=iChng; i--){ + Stat4Sample *pBest = &p->aBest[i]; + pBest->anEq[i] = p->current.anEq[i]; + if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){ + sampleInsert(p, pBest, i); + } + } + + /* Update the anEq[] fields of any samples already collected. */ + for(i=p->nSample-1; i>=0; i--){ + int j; + for(j=iChng; j<p->nCol; j++){ + if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j]; + } + } +#endif + +#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4) + if( iChng==0 ){ + tRowcnt nLt = p->current.anLt[0]; + tRowcnt nEq = p->current.anEq[0]; + + /* Check if this is to be a periodic sample. If so, add it. */ + if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){ + p->current.isPSample = 1; + sampleInsert(p, &p->current, 0); + p->current.isPSample = 0; + }else + + /* Or if it is a non-periodic sample. Add it in this case too. */ + if( p->nSample<p->mxSample + || sampleIsBetter(p, &p->current, &p->a[p->iMin]) + ){ + sampleInsert(p, &p->current, 0); + } + } +#endif + +#ifndef SQLITE_ENABLE_STAT3_OR_STAT4 + UNUSED_PARAMETER( p ); + UNUSED_PARAMETER( iChng ); +#endif +} /* -** Implementation of the stat3_push(nEq,nLt,nDLt,rowid,P) SQL function. The -** arguments describe a single key instance. This routine makes the -** decision about whether or not to retain this key for the sqlite_stat3 -** table. +** Implementation of the stat_push SQL function: stat_push(P,C,R) +** Arguments: +** +** P Pointer to the Stat4Accum object created by stat_init() +** C Index of left-most column to differ from previous row +** R Rowid for the current row. Might be a key record for +** WITHOUT ROWID tables. ** -** The return value is NULL. +** This SQL function always returns NULL. It's purpose it to accumulate +** statistical data and/or samples in the Stat4Accum object about the +** index being analyzed. The stat_get() SQL function will later be used to +** extract relevant information for constructing the sqlite_statN tables. +** +** The R parameter is only used for STAT3 and STAT4 */ -static void stat3Push( +static void statPush( sqlite3_context *context, int argc, sqlite3_value **argv ){ - Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[4]); - tRowcnt nEq = sqlite3_value_int64(argv[0]); - tRowcnt nLt = sqlite3_value_int64(argv[1]); - tRowcnt nDLt = sqlite3_value_int64(argv[2]); - i64 rowid = sqlite3_value_int64(argv[3]); - u8 isPSample = 0; - u8 doInsert = 0; - int iMin = p->iMin; - struct Stat3Sample *pSample; int i; - u32 h; - UNUSED_PARAMETER(context); - UNUSED_PARAMETER(argc); - if( nEq==0 ) return; - h = p->iPrn = p->iPrn*1103515245 + 12345; - if( (nLt/p->nPSample)!=((nEq+nLt)/p->nPSample) ){ - doInsert = isPSample = 1; - }else if( p->nSample<p->mxSample ){ - doInsert = 1; + /* The three function arguments */ + Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]); + int iChng = sqlite3_value_int(argv[1]); + + UNUSED_PARAMETER( argc ); + UNUSED_PARAMETER( context ); + assert( p->nCol>0 ); + assert( iChng<p->nCol ); + + if( p->nRow==0 ){ + /* This is the first call to this function. Do initialization. */ + for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1; }else{ - if( nEq>p->a[iMin].nEq || (nEq==p->a[iMin].nEq && h>p->a[iMin].iHash) ){ - doInsert = 1; + /* Second and subsequent calls get processed here */ + samplePushPrevious(p, iChng); + + /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply + ** to the current row of the index. */ + for(i=0; i<iChng; i++){ + p->current.anEq[i]++; + } + for(i=iChng; i<p->nCol; i++){ + p->current.anDLt[i]++; +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + p->current.anLt[i] += p->current.anEq[i]; +#endif + p->current.anEq[i] = 1; } } - if( !doInsert ) return; - if( p->nSample==p->mxSample ){ - assert( p->nSample - iMin - 1 >= 0 ); - memmove(&p->a[iMin], &p->a[iMin+1], sizeof(p->a[0])*(p->nSample-iMin-1)); - pSample = &p->a[p->nSample-1]; + p->nRow++; +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){ + sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2])); }else{ - pSample = &p->a[p->nSample++]; + sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]), + sqlite3_value_blob(argv[2])); } - pSample->iRowid = rowid; - pSample->nEq = nEq; - pSample->nLt = nLt; - pSample->nDLt = nDLt; - pSample->iHash = h; - pSample->isPSample = isPSample; - - /* Find the new minimum */ - if( p->nSample==p->mxSample ){ - pSample = p->a; - i = 0; - while( pSample->isPSample ){ - i++; - pSample++; - assert( i<p->nSample ); + p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345; +#endif + +#ifdef SQLITE_ENABLE_STAT4 + { + tRowcnt nLt = p->current.anLt[p->nCol-1]; + + /* Check if this is to be a periodic sample. If so, add it. */ + if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){ + p->current.isPSample = 1; + p->current.iCol = 0; + sampleInsert(p, &p->current, p->nCol-1); + p->current.isPSample = 0; } - nEq = pSample->nEq; - h = pSample->iHash; - iMin = i; - for(i++, pSample++; i<p->nSample; i++, pSample++){ - if( pSample->isPSample ) continue; - if( pSample->nEq<nEq - || (pSample->nEq==nEq && pSample->iHash<h) - ){ - iMin = i; - nEq = pSample->nEq; - h = pSample->iHash; + + /* Update the aBest[] array. */ + for(i=0; i<(p->nCol-1); i++){ + p->current.iCol = i; + if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){ + sampleCopy(p, &p->aBest[i], &p->current); } } - p->iMin = iMin; } +#endif } -static const FuncDef stat3PushFuncdef = { - 5, /* nArg */ - SQLITE_UTF8, /* iPrefEnc */ - 0, /* flags */ - 0, /* pUserData */ - 0, /* pNext */ - stat3Push, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat3_push", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ +static const FuncDef statPushFuncdef = { + 2+IsStat34, /* nArg */ + SQLITE_UTF8, /* funcFlags */ + 0, /* pUserData */ + 0, /* pNext */ + statPush, /* xFunc */ + 0, /* xStep */ + 0, /* xFinalize */ + "stat_push", /* zName */ + 0, /* pHash */ + 0 /* pDestructor */ }; +#define STAT_GET_STAT1 0 /* "stat" column of stat1 table */ +#define STAT_GET_ROWID 1 /* "rowid" column of stat[34] entry */ +#define STAT_GET_NEQ 2 /* "neq" column of stat[34] entry */ +#define STAT_GET_NLT 3 /* "nlt" column of stat[34] entry */ +#define STAT_GET_NDLT 4 /* "ndlt" column of stat[34] entry */ + /* -** Implementation of the stat3_get(P,N,...) SQL function. This routine is -** used to query the results. Content is returned for the Nth sqlite_stat3 -** row where N is between 0 and S-1 and S is the number of samples. The -** value returned depends on the number of arguments. +** Implementation of the stat_get(P,J) SQL function. This routine is +** used to query statistical information that has been gathered into +** the Stat4Accum object by prior calls to stat_push(). The P parameter +** is a BLOB which is decoded into a pointer to the Stat4Accum objects. +** The content to returned is determined by the parameter J +** which is one of the STAT_GET_xxxx values defined above. ** -** argc==2 result: rowid -** argc==3 result: nEq -** argc==4 result: nLt -** argc==5 result: nDLt +** If neither STAT3 nor STAT4 are enabled, then J is always +** STAT_GET_STAT1 and is hence omitted and this routine becomes +** a one-parameter function, stat_get(P), that always returns the +** stat1 table entry information. */ -static void stat3Get( +static void statGet( sqlite3_context *context, int argc, sqlite3_value **argv ){ - int n = sqlite3_value_int(argv[1]); - Stat3Accum *p = (Stat3Accum*)sqlite3_value_blob(argv[0]); - - assert( p!=0 ); - if( p->nSample<=n ) return; - switch( argc ){ - case 2: sqlite3_result_int64(context, p->a[n].iRowid); break; - case 3: sqlite3_result_int64(context, p->a[n].nEq); break; - case 4: sqlite3_result_int64(context, p->a[n].nLt); break; - default: sqlite3_result_int64(context, p->a[n].nDLt); break; + Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]); +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + /* STAT3 and STAT4 have a parameter on this routine. */ + int eCall = sqlite3_value_int(argv[1]); + assert( argc==2 ); + assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ + || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT + || eCall==STAT_GET_NDLT + ); + if( eCall==STAT_GET_STAT1 ) +#else + assert( argc==1 ); +#endif + { + /* Return the value to store in the "stat" column of the sqlite_stat1 + ** table for this index. + ** + ** The value is a string composed of a list of integers describing + ** the index. The first integer in the list is the total number of + ** entries in the index. There is one additional integer in the list + ** for each indexed column. This additional integer is an estimate of + ** the number of rows matched by a stabbing query on the index using + ** a key with the corresponding number of fields. In other words, + ** if the index is on columns (a,b) and the sqlite_stat1 value is + ** "100 10 2", then SQLite estimates that: + ** + ** * the index contains 100 rows, + ** * "WHERE a=?" matches 10 rows, and + ** * "WHERE a=? AND b=?" matches 2 rows. + ** + ** If D is the count of distinct values and K is the total number of + ** rows, then each estimate is computed as: + ** + ** I = (K+D-1)/D + */ + char *z; + int i; + + char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 ); + if( zRet==0 ){ + sqlite3_result_error_nomem(context); + return; + } + + sqlite3_snprintf(24, zRet, "%llu", (u64)p->nRow); + z = zRet + sqlite3Strlen30(zRet); + for(i=0; i<p->nKeyCol; i++){ + u64 nDistinct = p->current.anDLt[i] + 1; + u64 iVal = (p->nRow + nDistinct - 1) / nDistinct; + sqlite3_snprintf(24, z, " %llu", iVal); + z += sqlite3Strlen30(z); + assert( p->current.anEq[i] ); + } + assert( z[0]=='\0' && z>zRet ); + + sqlite3_result_text(context, zRet, -1, sqlite3_free); } +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + else if( eCall==STAT_GET_ROWID ){ + if( p->iGet<0 ){ + samplePushPrevious(p, 0); + p->iGet = 0; + } + if( p->iGet<p->nSample ){ + Stat4Sample *pS = p->a + p->iGet; + if( pS->nRowid==0 ){ + sqlite3_result_int64(context, pS->u.iRowid); + }else{ + sqlite3_result_blob(context, pS->u.aRowid, pS->nRowid, + SQLITE_TRANSIENT); + } + } + }else{ + tRowcnt *aCnt = 0; + + assert( p->iGet<p->nSample ); + switch( eCall ){ + case STAT_GET_NEQ: aCnt = p->a[p->iGet].anEq; break; + case STAT_GET_NLT: aCnt = p->a[p->iGet].anLt; break; + default: { + aCnt = p->a[p->iGet].anDLt; + p->iGet++; + break; + } + } + + if( IsStat3 ){ + sqlite3_result_int64(context, (i64)aCnt[0]); + }else{ + char *zRet = sqlite3MallocZero(p->nCol * 25); + if( zRet==0 ){ + sqlite3_result_error_nomem(context); + }else{ + int i; + char *z = zRet; + for(i=0; i<p->nCol; i++){ + sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]); + z += sqlite3Strlen30(z); + } + assert( z[0]=='\0' && z>zRet ); + z[-1] = '\0'; + sqlite3_result_text(context, zRet, -1, sqlite3_free); + } + } + } +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ +#ifndef SQLITE_DEBUG + UNUSED_PARAMETER( argc ); +#endif } -static const FuncDef stat3GetFuncdef = { - -1, /* nArg */ - SQLITE_UTF8, /* iPrefEnc */ - 0, /* flags */ - 0, /* pUserData */ - 0, /* pNext */ - stat3Get, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat3_get", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ +static const FuncDef statGetFuncdef = { + 1+IsStat34, /* nArg */ + SQLITE_UTF8, /* funcFlags */ + 0, /* pUserData */ + 0, /* pNext */ + statGet, /* xFunc */ + 0, /* xStep */ + 0, /* xFinalize */ + "stat_get", /* zName */ + 0, /* pHash */ + 0 /* pDestructor */ }; -#endif /* SQLITE_ENABLE_STAT3 */ - - +static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){ + assert( regOut!=regStat4 && regOut!=regStat4+1 ); +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1); +#elif SQLITE_DEBUG + assert( iParam==STAT_GET_STAT1 ); +#else + UNUSED_PARAMETER( iParam ); +#endif + sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4, regOut); + sqlite3VdbeChangeP4(v, -1, (char*)&statGetFuncdef, P4_FUNCDEF); + sqlite3VdbeChangeP5(v, 1 + IsStat34); +} /* ** Generate code to do an analysis of all indices associated with @@ -430,41 +953,31 @@ static void analyzeOneTable( Table *pTab, /* Table whose indices are to be analyzed */ Index *pOnlyIdx, /* If not NULL, only analyze this one index */ int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */ - int iMem /* Available memory locations begin here */ + int iMem, /* Available memory locations begin here */ + int iTab /* Next available cursor */ ){ sqlite3 *db = pParse->db; /* Database handle */ Index *pIdx; /* An index to being analyzed */ int iIdxCur; /* Cursor open on index being analyzed */ + int iTabCur; /* Table cursor */ Vdbe *v; /* The virtual machine being built up */ int i; /* Loop counter */ - int topOfLoop; /* The top of the loop */ - int endOfLoop; /* The end of the loop */ int jZeroRows = -1; /* Jump from here if number of rows is zero */ int iDb; /* Index of database containing pTab */ - int regTabname = iMem++; /* Register containing table name */ - int regIdxname = iMem++; /* Register containing index name */ - int regStat1 = iMem++; /* The stat column of sqlite_stat1 */ -#ifdef SQLITE_ENABLE_STAT3 - int regNumEq = regStat1; /* Number of instances. Same as regStat1 */ - int regNumLt = iMem++; /* Number of keys less than regSample */ - int regNumDLt = iMem++; /* Number of distinct keys less than regSample */ - int regSample = iMem++; /* The next sample value */ - int regRowid = regSample; /* Rowid of a sample */ - int regAccum = iMem++; /* Register to hold Stat3Accum object */ - int regLoop = iMem++; /* Loop counter */ - int regCount = iMem++; /* Number of rows in the table or index */ - int regTemp1 = iMem++; /* Intermediate register */ - int regTemp2 = iMem++; /* Intermediate register */ - int once = 1; /* One-time initialization */ - int shortJump = 0; /* Instruction address */ - int iTabCur = pParse->nTab++; /* Table cursor */ + u8 needTableCnt = 1; /* True to count the table */ + int regNewRowid = iMem++; /* Rowid for the inserted record */ + int regStat4 = iMem++; /* Register to hold Stat4Accum object */ + int regChng = iMem++; /* Index of changed index field */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + int regRowid = iMem++; /* Rowid argument passed to stat_push() */ #endif - int regCol = iMem++; /* Content of a column in analyzed table */ - int regRec = iMem++; /* Register holding completed record */ int regTemp = iMem++; /* Temporary use register */ - int regNewRowid = iMem++; /* Rowid for the inserted record */ - + int regTabname = iMem++; /* Register containing table name */ + int regIdxname = iMem++; /* Register containing index name */ + int regStat1 = iMem++; /* Value for the stat column of sqlite_stat1 */ + int regPrev = iMem; /* MUST BE LAST (see below) */ + pParse->nMem = MAX(pParse->nMem, iMem); v = sqlite3GetVdbe(pParse); if( v==0 || NEVER(pTab==0) ){ return; @@ -488,215 +1001,271 @@ static void analyzeOneTable( } #endif - /* Establish a read-lock on the table at the shared-cache level. */ + /* Establish a read-lock on the table at the shared-cache level. + ** Open a read-only cursor on the table. Also allocate a cursor number + ** to use for scanning indexes (iIdxCur). No index cursor is opened at + ** this time though. */ sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); - - iIdxCur = pParse->nTab++; + iTabCur = iTab++; + iIdxCur = iTab++; + pParse->nTab = MAX(pParse->nTab, iTab); + sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead); sqlite3VdbeAddOp4(v, OP_String8, 0, regTabname, 0, pTab->zName, 0); + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ - int nCol; - KeyInfo *pKey; - int addrIfNot = 0; /* address of OP_IfNot */ - int *aChngAddr; /* Array of jump instruction addresses */ + int nCol; /* Number of columns in pIdx. "N" */ + int addrRewind; /* Address of "OP_Rewind iIdxCur" */ + int addrNextRow; /* Address of "next_row:" */ + const char *zIdxName; /* Name of the index */ + int nColTest; /* Number of columns to test for changes */ if( pOnlyIdx && pOnlyIdx!=pIdx ) continue; - VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName)); - nCol = pIdx->nColumn; - aChngAddr = sqlite3DbMallocRaw(db, sizeof(int)*nCol); - if( aChngAddr==0 ) continue; - pKey = sqlite3IndexKeyinfo(pParse, pIdx); - if( iMem+1+(nCol*2)>pParse->nMem ){ - pParse->nMem = iMem+1+(nCol*2); + if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0; + if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){ + nCol = pIdx->nKeyCol; + zIdxName = pTab->zName; + nColTest = nCol - 1; + }else{ + nCol = pIdx->nColumn; + zIdxName = pIdx->zName; + nColTest = pIdx->uniqNotNull ? pIdx->nKeyCol-1 : nCol-1; } - /* Open a cursor to the index to be analyzed. */ - assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); - sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb, - (char *)pKey, P4_KEYINFO_HANDOFF); - VdbeComment((v, "%s", pIdx->zName)); - /* Populate the register containing the index name. */ - sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, pIdx->zName, 0); + sqlite3VdbeAddOp4(v, OP_String8, 0, regIdxname, 0, zIdxName, 0); + VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName)); -#ifdef SQLITE_ENABLE_STAT3 - if( once ){ - once = 0; - sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead); - } - sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regCount); - sqlite3VdbeAddOp2(v, OP_Integer, SQLITE_STAT3_SAMPLES, regTemp1); - sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumEq); - sqlite3VdbeAddOp2(v, OP_Integer, 0, regNumLt); - sqlite3VdbeAddOp2(v, OP_Integer, -1, regNumDLt); - sqlite3VdbeAddOp3(v, OP_Null, 0, regSample, regAccum); - sqlite3VdbeAddOp4(v, OP_Function, 1, regCount, regAccum, - (char*)&stat3InitFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 2); -#endif /* SQLITE_ENABLE_STAT3 */ - - /* The block of memory cells initialized here is used as follows. + /* + ** Pseudo-code for loop that calls stat_push(): + ** + ** Rewind csr + ** if eof(csr) goto end_of_scan; + ** regChng = 0 + ** goto chng_addr_0; ** - ** iMem: - ** The total number of rows in the table. + ** next_row: + ** regChng = 0 + ** if( idx(0) != regPrev(0) ) goto chng_addr_0 + ** regChng = 1 + ** if( idx(1) != regPrev(1) ) goto chng_addr_1 + ** ... + ** regChng = N + ** goto chng_addr_N ** - ** iMem+1 .. iMem+nCol: - ** Number of distinct entries in index considering the - ** left-most N columns only, where N is between 1 and nCol, - ** inclusive. + ** chng_addr_0: + ** regPrev(0) = idx(0) + ** chng_addr_1: + ** regPrev(1) = idx(1) + ** ... ** - ** iMem+nCol+1 .. Mem+2*nCol: - ** Previous value of indexed columns, from left to right. + ** endDistinctTest: + ** regRowid = idx(rowid) + ** stat_push(P, regChng, regRowid) + ** Next csr + ** if !eof(csr) goto next_row; ** - ** Cells iMem through iMem+nCol are initialized to 0. The others are - ** initialized to contain an SQL NULL. + ** end_of_scan: */ - for(i=0; i<=nCol; i++){ - sqlite3VdbeAddOp2(v, OP_Integer, 0, iMem+i); - } - for(i=0; i<nCol; i++){ - sqlite3VdbeAddOp2(v, OP_Null, 0, iMem+nCol+i+1); - } - /* Start the analysis loop. This loop runs through all the entries in - ** the index b-tree. */ - endOfLoop = sqlite3VdbeMakeLabel(v); - sqlite3VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop); - topOfLoop = sqlite3VdbeCurrentAddr(v); - sqlite3VdbeAddOp2(v, OP_AddImm, iMem, 1); /* Increment row counter */ - - for(i=0; i<nCol; i++){ - CollSeq *pColl; - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regCol); - if( i==0 ){ - /* Always record the very first row */ - addrIfNot = sqlite3VdbeAddOp1(v, OP_IfNot, iMem+1); - } - assert( pIdx->azColl!=0 ); - assert( pIdx->azColl[i]!=0 ); - pColl = sqlite3LocateCollSeq(pParse, pIdx->azColl[i]); - aChngAddr[i] = sqlite3VdbeAddOp4(v, OP_Ne, regCol, 0, iMem+nCol+i+1, - (char*)pColl, P4_COLLSEQ); - sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); - VdbeComment((v, "jump if column %d changed", i)); -#ifdef SQLITE_ENABLE_STAT3 - if( i==0 ){ - sqlite3VdbeAddOp2(v, OP_AddImm, regNumEq, 1); - VdbeComment((v, "incr repeat count")); - } -#endif - } - sqlite3VdbeAddOp2(v, OP_Goto, 0, endOfLoop); - for(i=0; i<nCol; i++){ - sqlite3VdbeJumpHere(v, aChngAddr[i]); /* Set jump dest for the OP_Ne */ - if( i==0 ){ - sqlite3VdbeJumpHere(v, addrIfNot); /* Jump dest for OP_IfNot */ -#ifdef SQLITE_ENABLE_STAT3 - sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2, - (char*)&stat3PushFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 5); - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, pIdx->nColumn, regRowid); - sqlite3VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regNumLt); - sqlite3VdbeAddOp2(v, OP_AddImm, regNumDLt, 1); - sqlite3VdbeAddOp2(v, OP_Integer, 1, regNumEq); -#endif - } - sqlite3VdbeAddOp2(v, OP_AddImm, iMem+i+1, 1); - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, iMem+nCol+i+1); - } - sqlite3DbFree(db, aChngAddr); + /* Make sure there are enough memory cells allocated to accommodate + ** the regPrev array and a trailing rowid (the rowid slot is required + ** when building a record to insert into the sample column of + ** the sqlite_stat4 table. */ + pParse->nMem = MAX(pParse->nMem, regPrev+nColTest); - /* Always jump here after updating the iMem+1...iMem+1+nCol counters */ - sqlite3VdbeResolveLabel(v, endOfLoop); + /* Open a read-only cursor on the index being analyzed. */ + assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); + sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb); + sqlite3VdbeSetP4KeyInfo(pParse, pIdx); + VdbeComment((v, "%s", pIdx->zName)); - sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop); - sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); -#ifdef SQLITE_ENABLE_STAT3 - sqlite3VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2, - (char*)&stat3PushFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 5); - sqlite3VdbeAddOp2(v, OP_Integer, -1, regLoop); - shortJump = - sqlite3VdbeAddOp2(v, OP_AddImm, regLoop, 1); - sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regTemp1, - (char*)&stat3GetFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 2); - sqlite3VdbeAddOp1(v, OP_IsNull, regTemp1); - sqlite3VdbeAddOp3(v, OP_NotExists, iTabCur, shortJump, regTemp1); - sqlite3VdbeAddOp3(v, OP_Column, iTabCur, pIdx->aiColumn[0], regSample); - sqlite3ColumnDefault(v, pTab, pIdx->aiColumn[0], regSample); - sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumEq, - (char*)&stat3GetFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 3); - sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumLt, - (char*)&stat3GetFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 4); - sqlite3VdbeAddOp4(v, OP_Function, 1, regAccum, regNumDLt, - (char*)&stat3GetFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 5); - sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 6, regRec, "bbbbbb", 0); - sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regRec, regNewRowid); - sqlite3VdbeAddOp2(v, OP_Goto, 0, shortJump); - sqlite3VdbeJumpHere(v, shortJump+2); -#endif - - /* Store the results in sqlite_stat1. + /* Invoke the stat_init() function. The arguments are: + ** + ** (1) the number of columns in the index including the rowid + ** (or for a WITHOUT ROWID table, the number of PK columns), + ** (2) the number of columns in the key without the rowid/pk + ** (3) the number of rows in the index, ** - ** The result is a single row of the sqlite_stat1 table. The first - ** two columns are the names of the table and index. The third column - ** is a string composed of a list of integer statistics about the - ** index. The first integer in the list is the total number of entries - ** in the index. There is one additional integer in the list for each - ** column of the table. This additional integer is a guess of how many - ** rows of the table the index will select. If D is the count of distinct - ** values and K is the total number of rows, then the integer is computed - ** as: ** - ** I = (K+D-1)/D + ** The third argument is only used for STAT3 and STAT4 + */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3); +#endif + sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1); + sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2); + sqlite3VdbeAddOp3(v, OP_Function, 0, regStat4+1, regStat4); + sqlite3VdbeChangeP4(v, -1, (char*)&statInitFuncdef, P4_FUNCDEF); + sqlite3VdbeChangeP5(v, 2+IsStat34); + + /* Implementation of the following: + ** + ** Rewind csr + ** if eof(csr) goto end_of_scan; + ** regChng = 0 + ** goto next_push_0; ** - ** If K==0 then no entry is made into the sqlite_stat1 table. - ** If K>0 then it is always the case the D>0 so division by zero - ** is never possible. */ - sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regStat1); - if( jZeroRows<0 ){ - jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem); + addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur); + VdbeCoverage(v); + sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng); + addrNextRow = sqlite3VdbeCurrentAddr(v); + + if( nColTest>0 ){ + int endDistinctTest = sqlite3VdbeMakeLabel(v); + int *aGotoChng; /* Array of jump instruction addresses */ + aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*nColTest); + if( aGotoChng==0 ) continue; + + /* + ** next_row: + ** regChng = 0 + ** if( idx(0) != regPrev(0) ) goto chng_addr_0 + ** regChng = 1 + ** if( idx(1) != regPrev(1) ) goto chng_addr_1 + ** ... + ** regChng = N + ** goto endDistinctTest + */ + sqlite3VdbeAddOp0(v, OP_Goto); + addrNextRow = sqlite3VdbeCurrentAddr(v); + if( nColTest==1 && pIdx->nKeyCol==1 && IsUniqueIndex(pIdx) ){ + /* For a single-column UNIQUE index, once we have found a non-NULL + ** row, we know that all the rest will be distinct, so skip + ** subsequent distinctness tests. */ + sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest); + VdbeCoverage(v); + } + for(i=0; i<nColTest; i++){ + char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]); + sqlite3VdbeAddOp2(v, OP_Integer, i, regChng); + sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp); + aGotoChng[i] = + sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ); + sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); + VdbeCoverage(v); + } + sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng); + sqlite3VdbeAddOp2(v, OP_Goto, 0, endDistinctTest); + + + /* + ** chng_addr_0: + ** regPrev(0) = idx(0) + ** chng_addr_1: + ** regPrev(1) = idx(1) + ** ... + */ + sqlite3VdbeJumpHere(v, addrNextRow-1); + for(i=0; i<nColTest; i++){ + sqlite3VdbeJumpHere(v, aGotoChng[i]); + sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i); + } + sqlite3VdbeResolveLabel(v, endDistinctTest); + sqlite3DbFree(db, aGotoChng); } - for(i=0; i<nCol; i++){ - sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0); - sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1); - sqlite3VdbeAddOp3(v, OP_Add, iMem, iMem+i+1, regTemp); - sqlite3VdbeAddOp2(v, OP_AddImm, regTemp, -1); - sqlite3VdbeAddOp3(v, OP_Divide, iMem+i+1, regTemp, regTemp); - sqlite3VdbeAddOp1(v, OP_ToInt, regTemp); - sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1); + + /* + ** chng_addr_N: + ** regRowid = idx(rowid) // STAT34 only + ** stat_push(P, regChng, regRowid) // 3rd parameter STAT34 only + ** Next csr + ** if !eof(csr) goto next_row; + */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + assert( regRowid==(regStat4+2) ); + if( HasRowid(pTab) ){ + sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid); + }else{ + Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable); + int j, k, regKey; + regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol); + for(j=0; j<pPk->nKeyCol; j++){ + k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]); + sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j); + VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName)); + } + sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid); + sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol); } - sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); +#endif + assert( regChng==(regStat4+1) ); + sqlite3VdbeAddOp3(v, OP_Function, 1, regStat4, regTemp); + sqlite3VdbeChangeP4(v, -1, (char*)&statPushFuncdef, P4_FUNCDEF); + sqlite3VdbeChangeP5(v, 2+IsStat34); + sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v); + + /* Add the entry to the stat1 table. */ + callStatGet(v, regStat4, STAT_GET_STAT1, regStat1); + sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "aaa", 0); sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid); + sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); + + /* Add the entries to the stat3 or stat4 table. */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + { + int regEq = regStat1; + int regLt = regStat1+1; + int regDLt = regStat1+2; + int regSample = regStat1+3; + int regCol = regStat1+4; + int regSampleRowid = regCol + nCol; + int addrNext; + int addrIsNull; + u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound; + + pParse->nMem = MAX(pParse->nMem, regCol+nCol); + + addrNext = sqlite3VdbeCurrentAddr(v); + callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid); + addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid); + VdbeCoverage(v); + callStatGet(v, regStat4, STAT_GET_NEQ, regEq); + callStatGet(v, regStat4, STAT_GET_NLT, regLt); + callStatGet(v, regStat4, STAT_GET_NDLT, regDLt); + sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0); + /* We know that the regSampleRowid row exists because it was read by + ** the previous loop. Thus the not-found jump of seekOp will never + ** be taken */ + VdbeCoverageNeverTaken(v); +#ifdef SQLITE_ENABLE_STAT3 + sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, + pIdx->aiColumn[0], regSample); +#else + for(i=0; i<nCol; i++){ + i16 iCol = pIdx->aiColumn[i]; + sqlite3ExprCodeGetColumnOfTable(v, pTab, iTabCur, iCol, regCol+i); + } + sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample); +#endif + sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp); + sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid); + sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid); + sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */ + sqlite3VdbeJumpHere(v, addrIsNull); + } +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ + + /* End of analysis */ + sqlite3VdbeJumpHere(v, addrRewind); } - /* If the table has no indices, create a single sqlite_stat1 entry - ** containing NULL as the index name and the row count as the content. + + /* Create a single sqlite_stat1 entry containing NULL as the index + ** name and the row count as the content. */ - if( pTab->pIndex==0 ){ - sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb); + if( pOnlyIdx==0 && needTableCnt ){ VdbeComment((v, "%s", pTab->zName)); - sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat1); - sqlite3VdbeAddOp1(v, OP_Close, iIdxCur); - jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1); - }else{ + sqlite3VdbeAddOp2(v, OP_Count, iTabCur, regStat1); + jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1); VdbeCoverage(v); + sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname); + sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "aaa", 0); + sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid); + sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid); + sqlite3VdbeChangeP5(v, OPFLAG_APPEND); sqlite3VdbeJumpHere(v, jZeroRows); - jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto); } - sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname); - sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0); - sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid); - sqlite3VdbeChangeP5(v, OPFLAG_APPEND); - if( pParse->nMem<regRec ) pParse->nMem = regRec; - sqlite3VdbeJumpHere(v, jZeroRows); } @@ -720,16 +1289,18 @@ static void analyzeDatabase(Parse *pParse, int iDb){ HashElem *k; int iStatCur; int iMem; + int iTab; sqlite3BeginWriteOperation(pParse, 0, iDb); iStatCur = pParse->nTab; pParse->nTab += 3; openStatTable(pParse, iDb, iStatCur, 0, 0); iMem = pParse->nMem+1; + iTab = pParse->nTab; assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){ Table *pTab = (Table*)sqliteHashData(k); - analyzeOneTable(pParse, pTab, 0, iStatCur, iMem); + analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab); } loadAnalysis(pParse, iDb); } @@ -754,7 +1325,7 @@ static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){ }else{ openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl"); } - analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur, pParse->nMem+1); + analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur,pParse->nMem+1,pParse->nTab); loadAnalysis(pParse, iDb); } @@ -778,6 +1349,7 @@ void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){ Table *pTab; Index *pIdx; Token *pTableName; + Vdbe *v; /* Read the database schema. If an error occurs, leave an error message ** and code in pParse and return NULL. */ @@ -825,6 +1397,8 @@ void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){ } } } + v = sqlite3GetVdbe(pParse); + if( v ) sqlite3VdbeAddOp0(v, OP_Expire); } /* @@ -838,6 +1412,68 @@ struct analysisInfo { }; /* +** The first argument points to a nul-terminated string containing a +** list of space separated integers. Read the first nOut of these into +** the array aOut[]. +*/ +static void decodeIntArray( + char *zIntArray, /* String containing int array to decode */ + int nOut, /* Number of slots in aOut[] */ + tRowcnt *aOut, /* Store integers here */ + LogEst *aLog, /* Or, if aOut==0, here */ + Index *pIndex /* Handle extra flags for this index, if not NULL */ +){ + char *z = zIntArray; + int c; + int i; + tRowcnt v; + +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + if( z==0 ) z = ""; +#else + if( NEVER(z==0) ) z = ""; +#endif + for(i=0; *z && i<nOut; i++){ + v = 0; + while( (c=z[0])>='0' && c<='9' ){ + v = v*10 + c - '0'; + z++; + } +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + if( aOut ){ + aOut[i] = v; + }else +#else + assert( aOut==0 ); + UNUSED_PARAMETER(aOut); +#endif + { + aLog[i] = sqlite3LogEst(v); + } + if( *z==' ' ) z++; + } +#ifndef SQLITE_ENABLE_STAT3_OR_STAT4 + assert( pIndex!=0 ); +#else + if( pIndex ) +#endif + while( z[0] ){ + if( sqlite3_strglob("unordered*", z)==0 ){ + pIndex->bUnordered = 1; + }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){ + pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3)); + } +#ifdef SQLITE_ENABLE_COSTMULT + else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){ + pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9)); + } +#endif + while( z[0]!=0 && z[0]!=' ' ) z++; + while( z[0]==' ' ) z++; + } +} + +/* ** This callback is invoked once for each index when reading the ** sqlite_stat1 table. ** @@ -852,8 +1488,6 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){ analysisInfo *pInfo = (analysisInfo*)pData; Index *pIndex; Table *pTable; - int i, c, n; - tRowcnt v; const char *z; assert( argc==3 ); @@ -866,28 +1500,29 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){ if( pTable==0 ){ return 0; } - if( argv[1] ){ - pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase); - }else{ + if( argv[1]==0 ){ pIndex = 0; + }else if( sqlite3_stricmp(argv[0],argv[1])==0 ){ + pIndex = sqlite3PrimaryKeyIndex(pTable); + }else{ + pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase); } - n = pIndex ? pIndex->nColumn : 0; z = argv[2]; - for(i=0; *z && i<=n; i++){ - v = 0; - while( (c=z[0])>='0' && c<='9' ){ - v = v*10 + c - '0'; - z++; - } - if( i==0 ) pTable->nRowEst = v; - if( pIndex==0 ) break; - pIndex->aiRowEst[i] = v; - if( *z==' ' ) z++; - if( strcmp(z, "unordered")==0 ){ - pIndex->bUnordered = 1; - break; - } + + if( pIndex ){ + pIndex->bUnordered = 0; + decodeIntArray((char*)z, pIndex->nKeyCol+1, 0, pIndex->aiRowLogEst, pIndex); + if( pIndex->pPartIdxWhere==0 ) pTable->nRowLogEst = pIndex->aiRowLogEst[0]; + }else{ + Index fakeIdx; + fakeIdx.szIdxRow = pTable->szTabRow; +#ifdef SQLITE_ENABLE_COSTMULT + fakeIdx.pTable = pTable; +#endif + decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx); + pTable->szTabRow = fakeIdx.szIdxRow; } + return 0; } @@ -896,14 +1531,12 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){ ** and its contents. */ void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){ -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 if( pIdx->aSample ){ int j; for(j=0; j<pIdx->nSample; j++){ IndexSample *p = &pIdx->aSample[j]; - if( p->eType==SQLITE_TEXT || p->eType==SQLITE_BLOB ){ - sqlite3DbFree(db, p->u.z); - } + sqlite3DbFree(db, p->p); } sqlite3DbFree(db, pIdx->aSample); } @@ -914,31 +1547,100 @@ void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){ #else UNUSED_PARAMETER(db); UNUSED_PARAMETER(pIdx); -#endif +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ } -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* -** Load content from the sqlite_stat3 table into the Index.aSample[] -** arrays of all indices. +** Populate the pIdx->aAvgEq[] array based on the samples currently +** stored in pIdx->aSample[]. +*/ +static void initAvgEq(Index *pIdx){ + if( pIdx ){ + IndexSample *aSample = pIdx->aSample; + IndexSample *pFinal = &aSample[pIdx->nSample-1]; + int iCol; + int nCol = 1; + if( pIdx->nSampleCol>1 ){ + /* If this is stat4 data, then calculate aAvgEq[] values for all + ** sample columns except the last. The last is always set to 1, as + ** once the trailing PK fields are considered all index keys are + ** unique. */ + nCol = pIdx->nSampleCol-1; + pIdx->aAvgEq[nCol] = 1; + } + for(iCol=0; iCol<nCol; iCol++){ + int i; /* Used to iterate through samples */ + tRowcnt sumEq = 0; /* Sum of the nEq values */ + tRowcnt nSum = 0; /* Number of terms contributing to sumEq */ + tRowcnt avgEq = 0; + tRowcnt nDLt = pFinal->anDLt[iCol]; + + /* Set nSum to the number of distinct (iCol+1) field prefixes that + ** occur in the stat4 table for this index before pFinal. Set + ** sumEq to the sum of the nEq values for column iCol for the same + ** set (adding the value only once where there exist dupicate + ** prefixes). */ + for(i=0; i<(pIdx->nSample-1); i++){ + if( aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] ){ + sumEq += aSample[i].anEq[iCol]; + nSum++; + } + } + if( nDLt>nSum ){ + avgEq = (pFinal->anLt[iCol] - sumEq)/(nDLt - nSum); + } + if( avgEq==0 ) avgEq = 1; + pIdx->aAvgEq[iCol] = avgEq; + } + } +} + +/* +** Look up an index by name. Or, if the name of a WITHOUT ROWID table +** is supplied instead, find the PRIMARY KEY index for that table. +*/ +static Index *findIndexOrPrimaryKey( + sqlite3 *db, + const char *zName, + const char *zDb +){ + Index *pIdx = sqlite3FindIndex(db, zName, zDb); + if( pIdx==0 ){ + Table *pTab = sqlite3FindTable(db, zName, zDb); + if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab); + } + return pIdx; +} + +/* +** Load the content from either the sqlite_stat4 or sqlite_stat3 table +** into the relevant Index.aSample[] arrays. +** +** Arguments zSql1 and zSql2 must point to SQL statements that return +** data equivalent to the following (statements are different for stat3, +** see the caller of this function for details): +** +** zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx +** zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4 +** +** where %Q is replaced with the database name before the SQL is executed. */ -static int loadStat3(sqlite3 *db, const char *zDb){ +static int loadStatTbl( + sqlite3 *db, /* Database handle */ + int bStat3, /* Assume single column records only */ + const char *zSql1, /* SQL statement 1 (see above) */ + const char *zSql2, /* SQL statement 2 (see above) */ + const char *zDb /* Database name (e.g. "main") */ +){ int rc; /* Result codes from subroutines */ sqlite3_stmt *pStmt = 0; /* An SQL statement being run */ char *zSql; /* Text of the SQL statement */ Index *pPrevIdx = 0; /* Previous index in the loop */ - int idx = 0; /* slot in pIdx->aSample[] for next sample */ - int eType; /* Datatype of a sample */ IndexSample *pSample; /* A slot in pIdx->aSample[] */ assert( db->lookaside.bEnabled==0 ); - if( !sqlite3FindTable(db, "sqlite_stat3", zDb) ){ - return SQLITE_OK; - } - - zSql = sqlite3MPrintf(db, - "SELECT idx,count(*) FROM %Q.sqlite_stat3" - " GROUP BY idx", zDb); + zSql = sqlite3MPrintf(db, zSql1, zDb); if( !zSql ){ return SQLITE_NOMEM; } @@ -947,30 +1649,54 @@ static int loadStat3(sqlite3 *db, const char *zDb){ if( rc ) return rc; while( sqlite3_step(pStmt)==SQLITE_ROW ){ + int nIdxCol = 1; /* Number of columns in stat4 records */ + char *zIndex; /* Index name */ Index *pIdx; /* Pointer to the index object */ int nSample; /* Number of samples */ + int nByte; /* Bytes of space required */ + int i; /* Bytes of space required */ + tRowcnt *pSpace; zIndex = (char *)sqlite3_column_text(pStmt, 0); if( zIndex==0 ) continue; nSample = sqlite3_column_int(pStmt, 1); - pIdx = sqlite3FindIndex(db, zIndex, zDb); - if( pIdx==0 ) continue; - assert( pIdx->nSample==0 ); - pIdx->nSample = nSample; - pIdx->aSample = sqlite3DbMallocZero(db, nSample*sizeof(IndexSample)); - pIdx->avgEq = pIdx->aiRowEst[1]; + pIdx = findIndexOrPrimaryKey(db, zIndex, zDb); + assert( pIdx==0 || bStat3 || pIdx->nSample==0 ); + /* Index.nSample is non-zero at this point if data has already been + ** loaded from the stat4 table. In this case ignore stat3 data. */ + if( pIdx==0 || pIdx->nSample ) continue; + if( bStat3==0 ){ + assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 ); + if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){ + nIdxCol = pIdx->nKeyCol; + }else{ + nIdxCol = pIdx->nColumn; + } + } + pIdx->nSampleCol = nIdxCol; + nByte = sizeof(IndexSample) * nSample; + nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample; + nByte += nIdxCol * sizeof(tRowcnt); /* Space for Index.aAvgEq[] */ + + pIdx->aSample = sqlite3DbMallocZero(db, nByte); if( pIdx->aSample==0 ){ - db->mallocFailed = 1; sqlite3_finalize(pStmt); return SQLITE_NOMEM; } + pSpace = (tRowcnt*)&pIdx->aSample[nSample]; + pIdx->aAvgEq = pSpace; pSpace += nIdxCol; + for(i=0; i<nSample; i++){ + pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol; + pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol; + pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol; + } + assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) ); } rc = sqlite3_finalize(pStmt); if( rc ) return rc; - zSql = sqlite3MPrintf(db, - "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat3", zDb); + zSql = sqlite3MPrintf(db, zSql2, zDb); if( !zSql ){ return SQLITE_NOMEM; } @@ -979,86 +1705,88 @@ static int loadStat3(sqlite3 *db, const char *zDb){ if( rc ) return rc; while( sqlite3_step(pStmt)==SQLITE_ROW ){ - char *zIndex; /* Index name */ - Index *pIdx; /* Pointer to the index object */ - int i; /* Loop counter */ - tRowcnt sumEq; /* Sum of the nEq values */ + char *zIndex; /* Index name */ + Index *pIdx; /* Pointer to the index object */ + int nCol = 1; /* Number of columns in index */ zIndex = (char *)sqlite3_column_text(pStmt, 0); if( zIndex==0 ) continue; - pIdx = sqlite3FindIndex(db, zIndex, zDb); + pIdx = findIndexOrPrimaryKey(db, zIndex, zDb); if( pIdx==0 ) continue; - if( pIdx==pPrevIdx ){ - idx++; - }else{ + /* This next condition is true if data has already been loaded from + ** the sqlite_stat4 table. In this case ignore stat3 data. */ + nCol = pIdx->nSampleCol; + if( bStat3 && nCol>1 ) continue; + if( pIdx!=pPrevIdx ){ + initAvgEq(pPrevIdx); pPrevIdx = pIdx; - idx = 0; } - assert( idx<pIdx->nSample ); - pSample = &pIdx->aSample[idx]; - pSample->nEq = (tRowcnt)sqlite3_column_int64(pStmt, 1); - pSample->nLt = (tRowcnt)sqlite3_column_int64(pStmt, 2); - pSample->nDLt = (tRowcnt)sqlite3_column_int64(pStmt, 3); - if( idx==pIdx->nSample-1 ){ - if( pSample->nDLt>0 ){ - for(i=0, sumEq=0; i<=idx-1; i++) sumEq += pIdx->aSample[i].nEq; - pIdx->avgEq = (pSample->nLt - sumEq)/pSample->nDLt; - } - if( pIdx->avgEq<=0 ) pIdx->avgEq = 1; - } - eType = sqlite3_column_type(pStmt, 4); - pSample->eType = (u8)eType; - switch( eType ){ - case SQLITE_INTEGER: { - pSample->u.i = sqlite3_column_int64(pStmt, 4); - break; - } - case SQLITE_FLOAT: { - pSample->u.r = sqlite3_column_double(pStmt, 4); - break; - } - case SQLITE_NULL: { - break; - } - default: assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); { - const char *z = (const char *)( - (eType==SQLITE_BLOB) ? - sqlite3_column_blob(pStmt, 4): - sqlite3_column_text(pStmt, 4) - ); - int n = z ? sqlite3_column_bytes(pStmt, 4) : 0; - pSample->nByte = n; - if( n < 1){ - pSample->u.z = 0; - }else{ - pSample->u.z = sqlite3DbMallocRaw(db, n); - if( pSample->u.z==0 ){ - db->mallocFailed = 1; - sqlite3_finalize(pStmt); - return SQLITE_NOMEM; - } - memcpy(pSample->u.z, z, n); - } - } + pSample = &pIdx->aSample[pIdx->nSample]; + decodeIntArray((char*)sqlite3_column_text(pStmt,1),nCol,pSample->anEq,0,0); + decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0); + decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0); + + /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer. + ** This is in case the sample record is corrupted. In that case, the + ** sqlite3VdbeRecordCompare() may read up to two varints past the + ** end of the allocated buffer before it realizes it is dealing with + ** a corrupt record. Adding the two 0x00 bytes prevents this from causing + ** a buffer overread. */ + pSample->n = sqlite3_column_bytes(pStmt, 4); + pSample->p = sqlite3DbMallocZero(db, pSample->n + 2); + if( pSample->p==0 ){ + sqlite3_finalize(pStmt); + return SQLITE_NOMEM; } + memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n); + pIdx->nSample++; } - return sqlite3_finalize(pStmt); + rc = sqlite3_finalize(pStmt); + if( rc==SQLITE_OK ) initAvgEq(pPrevIdx); + return rc; } -#endif /* SQLITE_ENABLE_STAT3 */ /* -** Load the content of the sqlite_stat1 and sqlite_stat3 tables. The +** Load content from the sqlite_stat4 and sqlite_stat3 tables into +** the Index.aSample[] arrays of all indices. +*/ +static int loadStat4(sqlite3 *db, const char *zDb){ + int rc = SQLITE_OK; /* Result codes from subroutines */ + + assert( db->lookaside.bEnabled==0 ); + if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){ + rc = loadStatTbl(db, 0, + "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", + "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4", + zDb + ); + } + + if( rc==SQLITE_OK && sqlite3FindTable(db, "sqlite_stat3", zDb) ){ + rc = loadStatTbl(db, 1, + "SELECT idx,count(*) FROM %Q.sqlite_stat3 GROUP BY idx", + "SELECT idx,neq,nlt,ndlt,sqlite_record(sample) FROM %Q.sqlite_stat3", + zDb + ); + } + + return rc; +} +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ + +/* +** Load the content of the sqlite_stat1 and sqlite_stat3/4 tables. The ** contents of sqlite_stat1 are used to populate the Index.aiRowEst[] -** arrays. The contents of sqlite_stat3 are used to populate the +** arrays. The contents of sqlite_stat3/4 are used to populate the ** Index.aSample[] arrays. ** ** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR -** is returned. In this case, even if SQLITE_ENABLE_STAT3 was defined -** during compilation and the sqlite_stat3 table is present, no data is +** is returned. In this case, even if SQLITE_ENABLE_STAT3/4 was defined +** during compilation and the sqlite_stat3/4 table is present, no data is ** read from it. ** -** If SQLITE_ENABLE_STAT3 was defined during compilation and the -** sqlite_stat3 table is not present in the database, SQLITE_ERROR is +** If SQLITE_ENABLE_STAT3/4 was defined during compilation and the +** sqlite_stat4 table is not present in the database, SQLITE_ERROR is ** returned. However, in this case, data is read from the sqlite_stat1 ** table (if it is present) before returning. ** @@ -1080,7 +1808,7 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){ for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){ Index *pIdx = sqliteHashData(i); sqlite3DefaultRowEst(pIdx); -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 sqlite3DeleteIndexSamples(db, pIdx); pIdx->aSample = 0; #endif @@ -1104,12 +1832,12 @@ int sqlite3AnalysisLoad(sqlite3 *db, int iDb){ } - /* Load the statistics from the sqlite_stat3 table. */ -#ifdef SQLITE_ENABLE_STAT3 + /* Load the statistics from the sqlite_stat4 table. */ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 if( rc==SQLITE_OK ){ int lookasideEnabled = db->lookaside.bEnabled; db->lookaside.bEnabled = 0; - rc = loadStat3(db, sInfo.zDatabase); + rc = loadStat4(db, sInfo.zDatabase); db->lookaside.bEnabled = lookasideEnabled; } #endif |