diff options
Diffstat (limited to 'src/where.c')
| -rw-r--r-- | src/where.c | 6317 |
1 files changed, 3561 insertions, 2756 deletions
diff --git a/src/where.c b/src/where.c index e614f4a..9c30136 100644 --- a/src/where.c +++ b/src/where.c @@ -17,290 +17,114 @@ ** indices, you might also think of this module as the "query optimizer". */ #include "sqliteInt.h" - - -/* -** Trace output macros -*/ -#if defined(SQLITE_TEST) || defined(SQLITE_DEBUG) -/***/ int sqlite3WhereTrace = 0; -#endif -#if defined(SQLITE_DEBUG) \ - && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE)) -# define WHERETRACE(X) if(sqlite3WhereTrace) sqlite3DebugPrintf X -#else -# define WHERETRACE(X) -#endif - -/* Forward reference -*/ -typedef struct WhereClause WhereClause; -typedef struct WhereMaskSet WhereMaskSet; -typedef struct WhereOrInfo WhereOrInfo; -typedef struct WhereAndInfo WhereAndInfo; -typedef struct WhereCost WhereCost; - -/* -** The query generator uses an array of instances of this structure to -** help it analyze the subexpressions of the WHERE clause. Each WHERE -** clause subexpression is separated from the others by AND operators, -** usually, or sometimes subexpressions separated by OR. -** -** All WhereTerms are collected into a single WhereClause structure. -** The following identity holds: -** -** WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm -** -** When a term is of the form: -** -** X <op> <expr> -** -** where X is a column name and <op> is one of certain operators, -** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the -** cursor number and column number for X. WhereTerm.eOperator records -** the <op> using a bitmask encoding defined by WO_xxx below. The -** use of a bitmask encoding for the operator allows us to search -** quickly for terms that match any of several different operators. -** -** A WhereTerm might also be two or more subterms connected by OR: -** -** (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR .... -** -** In this second case, wtFlag as the TERM_ORINFO set and eOperator==WO_OR -** and the WhereTerm.u.pOrInfo field points to auxiliary information that -** is collected about the -** -** If a term in the WHERE clause does not match either of the two previous -** categories, then eOperator==0. The WhereTerm.pExpr field is still set -** to the original subexpression content and wtFlags is set up appropriately -** but no other fields in the WhereTerm object are meaningful. -** -** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers, -** but they do so indirectly. A single WhereMaskSet structure translates -** cursor number into bits and the translated bit is stored in the prereq -** fields. The translation is used in order to maximize the number of -** bits that will fit in a Bitmask. The VDBE cursor numbers might be -** spread out over the non-negative integers. For example, the cursor -** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The WhereMaskSet -** translates these sparse cursor numbers into consecutive integers -** beginning with 0 in order to make the best possible use of the available -** bits in the Bitmask. So, in the example above, the cursor numbers -** would be mapped into integers 0 through 7. -** -** The number of terms in a join is limited by the number of bits -** in prereqRight and prereqAll. The default is 64 bits, hence SQLite -** is only able to process joins with 64 or fewer tables. -*/ -typedef struct WhereTerm WhereTerm; -struct WhereTerm { - Expr *pExpr; /* Pointer to the subexpression that is this term */ - int iParent; /* Disable pWC->a[iParent] when this term disabled */ - int leftCursor; /* Cursor number of X in "X <op> <expr>" */ - union { - int leftColumn; /* Column number of X in "X <op> <expr>" */ - WhereOrInfo *pOrInfo; /* Extra information if (eOperator & WO_OR)!=0 */ - WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */ - } u; - u16 eOperator; /* A WO_xx value describing <op> */ - u8 wtFlags; /* TERM_xxx bit flags. See below */ - u8 nChild; /* Number of children that must disable us */ - WhereClause *pWC; /* The clause this term is part of */ - Bitmask prereqRight; /* Bitmask of tables used by pExpr->pRight */ - Bitmask prereqAll; /* Bitmask of tables referenced by pExpr */ -}; - -/* -** Allowed values of WhereTerm.wtFlags -*/ -#define TERM_DYNAMIC 0x01 /* Need to call sqlite3ExprDelete(db, pExpr) */ -#define TERM_VIRTUAL 0x02 /* Added by the optimizer. Do not code */ -#define TERM_CODED 0x04 /* This term is already coded */ -#define TERM_COPIED 0x08 /* Has a child */ -#define TERM_ORINFO 0x10 /* Need to free the WhereTerm.u.pOrInfo object */ -#define TERM_ANDINFO 0x20 /* Need to free the WhereTerm.u.pAndInfo obj */ -#define TERM_OR_OK 0x40 /* Used during OR-clause processing */ -#ifdef SQLITE_ENABLE_STAT3 -# define TERM_VNULL 0x80 /* Manufactured x>NULL or x<=NULL term */ -#else -# define TERM_VNULL 0x00 /* Disabled if not using stat3 */ -#endif - -/* -** An instance of the following structure holds all information about a -** WHERE clause. Mostly this is a container for one or more WhereTerms. -** -** Explanation of pOuter: For a WHERE clause of the form -** -** a AND ((b AND c) OR (d AND e)) AND f -** -** There are separate WhereClause objects for the whole clause and for -** the subclauses "(b AND c)" and "(d AND e)". The pOuter field of the -** subclauses points to the WhereClause object for the whole clause. -*/ -struct WhereClause { - Parse *pParse; /* The parser context */ - WhereMaskSet *pMaskSet; /* Mapping of table cursor numbers to bitmasks */ - WhereClause *pOuter; /* Outer conjunction */ - u8 op; /* Split operator. TK_AND or TK_OR */ - u16 wctrlFlags; /* Might include WHERE_AND_ONLY */ - int nTerm; /* Number of terms */ - int nSlot; /* Number of entries in a[] */ - WhereTerm *a; /* Each a[] describes a term of the WHERE cluase */ -#if defined(SQLITE_SMALL_STACK) - WhereTerm aStatic[1]; /* Initial static space for a[] */ -#else - WhereTerm aStatic[8]; /* Initial static space for a[] */ -#endif -}; +#include "whereInt.h" /* -** A WhereTerm with eOperator==WO_OR has its u.pOrInfo pointer set to -** a dynamically allocated instance of the following structure. +** Return the estimated number of output rows from a WHERE clause */ -struct WhereOrInfo { - WhereClause wc; /* Decomposition into subterms */ - Bitmask indexable; /* Bitmask of all indexable tables in the clause */ -}; +u64 sqlite3WhereOutputRowCount(WhereInfo *pWInfo){ + return sqlite3LogEstToInt(pWInfo->nRowOut); +} /* -** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to -** a dynamically allocated instance of the following structure. +** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this +** WHERE clause returns outputs for DISTINCT processing. */ -struct WhereAndInfo { - WhereClause wc; /* The subexpression broken out */ -}; +int sqlite3WhereIsDistinct(WhereInfo *pWInfo){ + return pWInfo->eDistinct; +} /* -** An instance of the following structure keeps track of a mapping -** between VDBE cursor numbers and bits of the bitmasks in WhereTerm. -** -** The VDBE cursor numbers are small integers contained in -** SrcList_item.iCursor and Expr.iTable fields. For any given WHERE -** clause, the cursor numbers might not begin with 0 and they might -** contain gaps in the numbering sequence. But we want to make maximum -** use of the bits in our bitmasks. This structure provides a mapping -** from the sparse cursor numbers into consecutive integers beginning -** with 0. -** -** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask -** corresponds VDBE cursor number B. The A-th bit of a bitmask is 1<<A. -** -** For example, if the WHERE clause expression used these VDBE -** cursors: 4, 5, 8, 29, 57, 73. Then the WhereMaskSet structure -** would map those cursor numbers into bits 0 through 5. -** -** Note that the mapping is not necessarily ordered. In the example -** above, the mapping might go like this: 4->3, 5->1, 8->2, 29->0, -** 57->5, 73->4. Or one of 719 other combinations might be used. It -** does not really matter. What is important is that sparse cursor -** numbers all get mapped into bit numbers that begin with 0 and contain -** no gaps. +** Return TRUE if the WHERE clause returns rows in ORDER BY order. +** Return FALSE if the output needs to be sorted. */ -struct WhereMaskSet { - int n; /* Number of assigned cursor values */ - int ix[BMS]; /* Cursor assigned to each bit */ -}; +int sqlite3WhereIsOrdered(WhereInfo *pWInfo){ + return pWInfo->nOBSat; +} /* -** A WhereCost object records a lookup strategy and the estimated -** cost of pursuing that strategy. +** Return the VDBE address or label to jump to in order to continue +** immediately with the next row of a WHERE clause. */ -struct WhereCost { - WherePlan plan; /* The lookup strategy */ - double rCost; /* Overall cost of pursuing this search strategy */ - Bitmask used; /* Bitmask of cursors used by this plan */ -}; +int sqlite3WhereContinueLabel(WhereInfo *pWInfo){ + assert( pWInfo->iContinue!=0 ); + return pWInfo->iContinue; +} /* -** Bitmasks for the operators that indices are able to exploit. An -** OR-ed combination of these values can be used when searching for -** terms in the where clause. +** Return the VDBE address or label to jump to in order to break +** out of a WHERE loop. */ -#define WO_IN 0x001 -#define WO_EQ 0x002 -#define WO_LT (WO_EQ<<(TK_LT-TK_EQ)) -#define WO_LE (WO_EQ<<(TK_LE-TK_EQ)) -#define WO_GT (WO_EQ<<(TK_GT-TK_EQ)) -#define WO_GE (WO_EQ<<(TK_GE-TK_EQ)) -#define WO_MATCH 0x040 -#define WO_ISNULL 0x080 -#define WO_OR 0x100 /* Two or more OR-connected terms */ -#define WO_AND 0x200 /* Two or more AND-connected terms */ -#define WO_EQUIV 0x400 /* Of the form A==B, both columns */ -#define WO_NOOP 0x800 /* This term does not restrict search space */ - -#define WO_ALL 0xfff /* Mask of all possible WO_* values */ -#define WO_SINGLE 0x0ff /* Mask of all non-compound WO_* values */ +int sqlite3WhereBreakLabel(WhereInfo *pWInfo){ + return pWInfo->iBreak; +} /* -** Value for wsFlags returned by bestIndex() and stored in -** WhereLevel.wsFlags. These flags determine which search -** strategies are appropriate. -** -** The least significant 12 bits is reserved as a mask for WO_ values above. -** The WhereLevel.wsFlags field is usually set to WO_IN|WO_EQ|WO_ISNULL. -** But if the table is the right table of a left join, WhereLevel.wsFlags -** is set to WO_IN|WO_EQ. The WhereLevel.wsFlags field can then be used as -** the "op" parameter to findTerm when we are resolving equality constraints. -** ISNULL constraints will then not be used on the right table of a left -** join. Tickets #2177 and #2189. +** Return TRUE if an UPDATE or DELETE statement can operate directly on +** the rowids returned by a WHERE clause. Return FALSE if doing an +** UPDATE or DELETE might change subsequent WHERE clause results. +** +** If the ONEPASS optimization is used (if this routine returns true) +** then also write the indices of open cursors used by ONEPASS +** into aiCur[0] and aiCur[1]. iaCur[0] gets the cursor of the data +** table and iaCur[1] gets the cursor used by an auxiliary index. +** Either value may be -1, indicating that cursor is not used. +** Any cursors returned will have been opened for writing. +** +** aiCur[0] and aiCur[1] both get -1 if the where-clause logic is +** unable to use the ONEPASS optimization. */ -#define WHERE_ROWID_EQ 0x00001000 /* rowid=EXPR or rowid IN (...) */ -#define WHERE_ROWID_RANGE 0x00002000 /* rowid<EXPR and/or rowid>EXPR */ -#define WHERE_COLUMN_EQ 0x00010000 /* x=EXPR or x IN (...) or x IS NULL */ -#define WHERE_COLUMN_RANGE 0x00020000 /* x<EXPR and/or x>EXPR */ -#define WHERE_COLUMN_IN 0x00040000 /* x IN (...) */ -#define WHERE_COLUMN_NULL 0x00080000 /* x IS NULL */ -#define WHERE_INDEXED 0x000f0000 /* Anything that uses an index */ -#define WHERE_NOT_FULLSCAN 0x100f3000 /* Does not do a full table scan */ -#define WHERE_IN_ABLE 0x080f1000 /* Able to support an IN operator */ -#define WHERE_TOP_LIMIT 0x00100000 /* x<EXPR or x<=EXPR constraint */ -#define WHERE_BTM_LIMIT 0x00200000 /* x>EXPR or x>=EXPR constraint */ -#define WHERE_BOTH_LIMIT 0x00300000 /* Both x>EXPR and x<EXPR */ -#define WHERE_IDX_ONLY 0x00400000 /* Use index only - omit table */ -#define WHERE_ORDERED 0x00800000 /* Output will appear in correct order */ -#define WHERE_REVERSE 0x01000000 /* Scan in reverse order */ -#define WHERE_UNIQUE 0x02000000 /* Selects no more than one row */ -#define WHERE_ALL_UNIQUE 0x04000000 /* This and all prior have one row */ -#define WHERE_OB_UNIQUE 0x00004000 /* Values in ORDER BY columns are - ** different for every output row */ -#define WHERE_VIRTUALTABLE 0x08000000 /* Use virtual-table processing */ -#define WHERE_MULTI_OR 0x10000000 /* OR using multiple indices */ -#define WHERE_TEMP_INDEX 0x20000000 /* Uses an ephemeral index */ -#define WHERE_DISTINCT 0x40000000 /* Correct order for DISTINCT */ -#define WHERE_COVER_SCAN 0x80000000 /* Full scan of a covering index */ +int sqlite3WhereOkOnePass(WhereInfo *pWInfo, int *aiCur){ + memcpy(aiCur, pWInfo->aiCurOnePass, sizeof(int)*2); + return pWInfo->okOnePass; +} /* -** This module contains many separate subroutines that work together to -** find the best indices to use for accessing a particular table in a query. -** An instance of the following structure holds context information about the -** index search so that it can be more easily passed between the various -** routines. +** Move the content of pSrc into pDest */ -typedef struct WhereBestIdx WhereBestIdx; -struct WhereBestIdx { - Parse *pParse; /* Parser context */ - WhereClause *pWC; /* The WHERE clause */ - struct SrcList_item *pSrc; /* The FROM clause term to search */ - Bitmask notReady; /* Mask of cursors not available */ - Bitmask notValid; /* Cursors not available for any purpose */ - ExprList *pOrderBy; /* The ORDER BY clause */ - ExprList *pDistinct; /* The select-list if query is DISTINCT */ - sqlite3_index_info **ppIdxInfo; /* Index information passed to xBestIndex */ - int i, n; /* Which loop is being coded; # of loops */ - WhereLevel *aLevel; /* Info about outer loops */ - WhereCost cost; /* Lowest cost query plan */ -}; +static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){ + pDest->n = pSrc->n; + memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0])); +} /* -** Return TRUE if the probe cost is less than the baseline cost +** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet. +** +** The new entry might overwrite an existing entry, or it might be +** appended, or it might be discarded. Do whatever is the right thing +** so that pSet keeps the N_OR_COST best entries seen so far. */ -static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){ - if( pProbe->rCost<pBaseline->rCost ) return 1; - if( pProbe->rCost>pBaseline->rCost ) return 0; - if( pProbe->plan.nOBSat>pBaseline->plan.nOBSat ) return 1; - if( pProbe->plan.nRow<pBaseline->plan.nRow ) return 1; - return 0; +static int whereOrInsert( + WhereOrSet *pSet, /* The WhereOrSet to be updated */ + Bitmask prereq, /* Prerequisites of the new entry */ + LogEst rRun, /* Run-cost of the new entry */ + LogEst nOut /* Number of outputs for the new entry */ +){ + u16 i; + WhereOrCost *p; + for(i=pSet->n, p=pSet->a; i>0; i--, p++){ + if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){ + goto whereOrInsert_done; + } + if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){ + return 0; + } + } + if( pSet->n<N_OR_COST ){ + p = &pSet->a[pSet->n++]; + p->nOut = nOut; + }else{ + p = pSet->a; + for(i=1; i<pSet->n; i++){ + if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i; + } + if( p->rRun<=rRun ) return 0; + } +whereOrInsert_done: + p->prereq = prereq; + p->rRun = rRun; + if( p->nOut>nOut ) p->nOut = nOut; + return 1; } /* @@ -308,17 +132,13 @@ static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){ */ static void whereClauseInit( WhereClause *pWC, /* The WhereClause to be initialized */ - Parse *pParse, /* The parsing context */ - WhereMaskSet *pMaskSet, /* Mapping from table cursor numbers to bitmasks */ - u16 wctrlFlags /* Might include WHERE_AND_ONLY */ + WhereInfo *pWInfo /* The WHERE processing context */ ){ - pWC->pParse = pParse; - pWC->pMaskSet = pMaskSet; + pWC->pWInfo = pWInfo; pWC->pOuter = 0; pWC->nTerm = 0; pWC->nSlot = ArraySize(pWC->aStatic); pWC->a = pWC->aStatic; - pWC->wctrlFlags = wctrlFlags; } /* Forward reference */ @@ -347,7 +167,7 @@ static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){ static void whereClauseClear(WhereClause *pWC){ int i; WhereTerm *a; - sqlite3 *db = pWC->pParse->db; + sqlite3 *db = pWC->pWInfo->pParse->db; for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){ if( a->wtFlags & TERM_DYNAMIC ){ sqlite3ExprDelete(db, a->pExpr); @@ -385,10 +205,10 @@ static void whereClauseClear(WhereClause *pWC){ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){ WhereTerm *pTerm; int idx; - testcase( wtFlags & TERM_VIRTUAL ); /* EV: R-00211-15100 */ + testcase( wtFlags & TERM_VIRTUAL ); if( pWC->nTerm>=pWC->nSlot ){ WhereTerm *pOld = pWC->a; - sqlite3 *db = pWC->pParse->db; + sqlite3 *db = pWC->pWInfo->pParse->db; pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 ); if( pWC->a==0 ){ if( wtFlags & TERM_DYNAMIC ){ @@ -404,6 +224,11 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){ pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]); } pTerm = &pWC->a[idx = pWC->nTerm++]; + if( p && ExprHasProperty(p, EP_Unlikely) ){ + pTerm->truthProb = sqlite3LogEst(p->iTable) - 99; + }else{ + pTerm->truthProb = 1; + } pTerm->pExpr = sqlite3ExprSkipCollate(p); pTerm->wtFlags = wtFlags; pTerm->pWC = pWC; @@ -428,8 +253,8 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){ ** the WhereClause.a[] array. The slot[] array grows as needed to contain ** all terms of the WHERE clause. */ -static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){ - pWC->op = (u8)op; +static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){ + pWC->op = op; if( pExpr==0 ) return; if( pExpr->op!=op ){ whereClauseInsert(pWC, pExpr, 0); @@ -440,9 +265,9 @@ static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){ } /* -** Initialize an expression mask set (a WhereMaskSet object) +** Initialize a WhereMaskSet object */ -#define initMaskSet(P) memset(P, 0, sizeof(*P)) +#define initMaskSet(P) (P)->n=0 /* ** Return the bitmask for the given cursor number. Return 0 if @@ -453,7 +278,7 @@ static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){ assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 ); for(i=0; i<pMaskSet->n; i++){ if( pMaskSet->ix[i]==iCursor ){ - return ((Bitmask)1)<<i; + return MASKBIT(i); } } return 0; @@ -473,18 +298,9 @@ static void createMask(WhereMaskSet *pMaskSet, int iCursor){ } /* -** This routine walks (recursively) an expression tree and generates +** These routines walk (recursively) an expression tree and generate ** a bitmask indicating which tables are used in that expression ** tree. -** -** In order for this routine to work, the calling function must have -** previously invoked sqlite3ResolveExprNames() on the expression. See -** the header comment on that routine for additional information. -** The sqlite3ResolveExprNames() routines looks for column names and -** sets their opcodes to TK_COLUMN and their Expr.iTable fields to -** the VDBE cursor number of the table. This routine just has to -** translate the cursor numbers into bitmask values and OR all -** the bitmasks together. */ static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*); static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*); @@ -538,14 +354,7 @@ static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){ /* ** Return TRUE if the given operator is one of the operators that is ** allowed for an indexable WHERE clause term. The allowed operators are -** "=", "<", ">", "<=", ">=", and "IN". -** -** IMPLEMENTATION-OF: R-59926-26393 To be usable by an index a term must be -** of one of the following forms: column = expression column > expression -** column >= expression column < expression column <= expression -** expression = column expression > column expression >= column -** expression < column expression <= column column IN -** (expression-list) column IN (subquery) column IS NULL +** "=", "<", ">", "<=", ">=", "IN", and "IS NULL" */ static int allowedOp(int op){ assert( TK_GT>TK_EQ && TK_GT<TK_GE ); @@ -565,10 +374,9 @@ static int allowedOp(int op){ ** are converted into "Y op X". ** ** If left/right precedence rules come into play when determining the -** collating -** side of the comparison, it remains associated with the same side after -** the commutation. So "Y collate NOCASE op X" becomes -** "X op Y". This is because any collation sequence on +** collating sequence, then COLLATE operators are adjusted to ensure +** that the collating sequence does not change. For example: +** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on ** the left hand side of a comparison overrides any collation sequence ** attached to the right. For the same reason the EP_Collate flag ** is not commuted. @@ -626,6 +434,133 @@ static u16 operatorMask(int op){ } /* +** Advance to the next WhereTerm that matches according to the criteria +** established when the pScan object was initialized by whereScanInit(). +** Return NULL if there are no more matching WhereTerms. +*/ +static WhereTerm *whereScanNext(WhereScan *pScan){ + int iCur; /* The cursor on the LHS of the term */ + int iColumn; /* The column on the LHS of the term. -1 for IPK */ + Expr *pX; /* An expression being tested */ + WhereClause *pWC; /* Shorthand for pScan->pWC */ + WhereTerm *pTerm; /* The term being tested */ + int k = pScan->k; /* Where to start scanning */ + + while( pScan->iEquiv<=pScan->nEquiv ){ + iCur = pScan->aEquiv[pScan->iEquiv-2]; + iColumn = pScan->aEquiv[pScan->iEquiv-1]; + while( (pWC = pScan->pWC)!=0 ){ + for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){ + if( pTerm->leftCursor==iCur + && pTerm->u.leftColumn==iColumn + && (pScan->iEquiv<=2 || !ExprHasProperty(pTerm->pExpr, EP_FromJoin)) + ){ + if( (pTerm->eOperator & WO_EQUIV)!=0 + && pScan->nEquiv<ArraySize(pScan->aEquiv) + ){ + int j; + pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight); + assert( pX->op==TK_COLUMN ); + for(j=0; j<pScan->nEquiv; j+=2){ + if( pScan->aEquiv[j]==pX->iTable + && pScan->aEquiv[j+1]==pX->iColumn ){ + break; + } + } + if( j==pScan->nEquiv ){ + pScan->aEquiv[j] = pX->iTable; + pScan->aEquiv[j+1] = pX->iColumn; + pScan->nEquiv += 2; + } + } + if( (pTerm->eOperator & pScan->opMask)!=0 ){ + /* Verify the affinity and collating sequence match */ + if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){ + CollSeq *pColl; + Parse *pParse = pWC->pWInfo->pParse; + pX = pTerm->pExpr; + if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){ + continue; + } + assert(pX->pLeft); + pColl = sqlite3BinaryCompareCollSeq(pParse, + pX->pLeft, pX->pRight); + if( pColl==0 ) pColl = pParse->db->pDfltColl; + if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){ + continue; + } + } + if( (pTerm->eOperator & WO_EQ)!=0 + && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN + && pX->iTable==pScan->aEquiv[0] + && pX->iColumn==pScan->aEquiv[1] + ){ + continue; + } + pScan->k = k+1; + return pTerm; + } + } + } + pScan->pWC = pScan->pWC->pOuter; + k = 0; + } + pScan->pWC = pScan->pOrigWC; + k = 0; + pScan->iEquiv += 2; + } + return 0; +} + +/* +** Initialize a WHERE clause scanner object. Return a pointer to the +** first match. Return NULL if there are no matches. +** +** The scanner will be searching the WHERE clause pWC. It will look +** for terms of the form "X <op> <expr>" where X is column iColumn of table +** iCur. The <op> must be one of the operators described by opMask. +** +** If the search is for X and the WHERE clause contains terms of the +** form X=Y then this routine might also return terms of the form +** "Y <op> <expr>". The number of levels of transitivity is limited, +** but is enough to handle most commonly occurring SQL statements. +** +** If X is not the INTEGER PRIMARY KEY then X must be compatible with +** index pIdx. +*/ +static WhereTerm *whereScanInit( + WhereScan *pScan, /* The WhereScan object being initialized */ + WhereClause *pWC, /* The WHERE clause to be scanned */ + int iCur, /* Cursor to scan for */ + int iColumn, /* Column to scan for */ + u32 opMask, /* Operator(s) to scan for */ + Index *pIdx /* Must be compatible with this index */ +){ + int j; + + /* memset(pScan, 0, sizeof(*pScan)); */ + pScan->pOrigWC = pWC; + pScan->pWC = pWC; + if( pIdx && iColumn>=0 ){ + pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity; + for(j=0; pIdx->aiColumn[j]!=iColumn; j++){ + if( NEVER(j>pIdx->nColumn) ) return 0; + } + pScan->zCollName = pIdx->azColl[j]; + }else{ + pScan->idxaff = 0; + pScan->zCollName = 0; + } + pScan->opMask = opMask; + pScan->k = 0; + pScan->aEquiv[0] = iCur; + pScan->aEquiv[1] = iColumn; + pScan->nEquiv = 2; + pScan->iEquiv = 2; + return whereScanNext(pScan); +} + +/* ** Search for a term in the WHERE clause that is of the form "X <op> <expr>" ** where X is a reference to the iColumn of table iCur and <op> is one of ** the WO_xx operator codes specified by the op parameter. @@ -656,84 +591,20 @@ static WhereTerm *findTerm( u32 op, /* Mask of WO_xx values describing operator */ Index *pIdx /* Must be compatible with this index, if not NULL */ ){ - WhereTerm *pTerm; /* Term being examined as possible result */ - WhereTerm *pResult = 0; /* The answer to return */ - WhereClause *pWCOrig = pWC; /* Original pWC value */ - int j, k; /* Loop counters */ - Expr *pX; /* Pointer to an expression */ - Parse *pParse; /* Parsing context */ - int iOrigCol = iColumn; /* Original value of iColumn */ - int nEquiv = 2; /* Number of entires in aEquiv[] */ - int iEquiv = 2; /* Number of entries of aEquiv[] processed so far */ - int aEquiv[22]; /* iCur,iColumn and up to 10 other equivalents */ - - assert( iCur>=0 ); - aEquiv[0] = iCur; - aEquiv[1] = iColumn; - for(;;){ - for(pWC=pWCOrig; pWC; pWC=pWC->pOuter){ - for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){ - if( pTerm->leftCursor==iCur - && pTerm->u.leftColumn==iColumn - ){ - if( (pTerm->prereqRight & notReady)==0 - && (pTerm->eOperator & op & WO_ALL)!=0 - ){ - if( iOrigCol>=0 && pIdx && (pTerm->eOperator & WO_ISNULL)==0 ){ - CollSeq *pColl; - char idxaff; - - pX = pTerm->pExpr; - pParse = pWC->pParse; - idxaff = pIdx->pTable->aCol[iOrigCol].affinity; - if( !sqlite3IndexAffinityOk(pX, idxaff) ){ - continue; - } - - /* Figure out the collation sequence required from an index for - ** it to be useful for optimising expression pX. Store this - ** value in variable pColl. - */ - assert(pX->pLeft); - pColl = sqlite3BinaryCompareCollSeq(pParse,pX->pLeft,pX->pRight); - if( pColl==0 ) pColl = pParse->db->pDfltColl; - - for(j=0; pIdx->aiColumn[j]!=iOrigCol; j++){ - if( NEVER(j>=pIdx->nColumn) ) return 0; - } - if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ){ - continue; - } - } - if( pTerm->prereqRight==0 && (pTerm->eOperator&WO_EQ)!=0 ){ - pResult = pTerm; - goto findTerm_success; - }else if( pResult==0 ){ - pResult = pTerm; - } - } - if( (pTerm->eOperator & WO_EQUIV)!=0 - && nEquiv<ArraySize(aEquiv) - ){ - pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight); - assert( pX->op==TK_COLUMN ); - for(j=0; j<nEquiv; j+=2){ - if( aEquiv[j]==pX->iTable && aEquiv[j+1]==pX->iColumn ) break; - } - if( j==nEquiv ){ - aEquiv[j] = pX->iTable; - aEquiv[j+1] = pX->iColumn; - nEquiv += 2; - } - } - } + WhereTerm *pResult = 0; + WhereTerm *p; + WhereScan scan; + + p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx); + while( p ){ + if( (p->prereqRight & notReady)==0 ){ + if( p->prereqRight==0 && (p->eOperator&WO_EQ)!=0 ){ + return p; } + if( pResult==0 ) pResult = p; } - if( iEquiv>=nEquiv ) break; - iCur = aEquiv[iEquiv++]; - iColumn = aEquiv[iEquiv++]; + p = whereScanNext(&scan); } -findTerm_success: return pResult; } @@ -742,8 +613,6 @@ static void exprAnalyze(SrcList*, WhereClause*, int); /* ** Call exprAnalyze on all terms in a WHERE clause. -** -** */ static void exprAnalyzeAll( SrcList *pTabList, /* the FROM clause */ @@ -799,15 +668,12 @@ static int isLikeOrGlob( } assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */ - pRight = pList->a[0].pExpr; + pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr); op = pRight->op; - if( op==TK_REGISTER ){ - op = pRight->op2; - } if( op==TK_VARIABLE ){ Vdbe *pReprepare = pParse->pReprepare; int iCol = pRight->iColumn; - pVal = sqlite3VdbeGetValue(pReprepare, iCol, SQLITE_AFF_NONE); + pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_NONE); if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){ z = (char *)sqlite3_value_text(pVal); } @@ -889,8 +755,10 @@ static int isMatchOfColumn( ** a join, then transfer the appropriate markings over to derived. */ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){ - pDerived->flags |= pBase->flags & EP_FromJoin; - pDerived->iRightJoinTable = pBase->iRightJoinTable; + if( pDerived ){ + pDerived->flags |= pBase->flags & EP_FromJoin; + pDerived->iRightJoinTable = pBase->iRightJoinTable; + } } #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY) @@ -949,10 +817,10 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){ ** From another point of view, "indexable" means that the subterm could ** potentially be used with an index if an appropriate index exists. ** This analysis does not consider whether or not the index exists; that -** is something the bestIndex() routine will determine. This analysis -** only looks at whether subterms appropriate for indexing exist. +** is decided elsewhere. This analysis only looks at whether subterms +** appropriate for indexing exist. ** -** All examples A through E above all satisfy case 2. But if a term +** All examples A through E above satisfy case 2. But if a term ** also statisfies case 1 (such as B) we know that the optimizer will ** always prefer case 1, so in that case we pretend that case 2 is not ** satisfied. @@ -975,11 +843,11 @@ static void exprAnalyzeOrTerm( WhereClause *pWC, /* the complete WHERE clause */ int idxTerm /* Index of the OR-term to be analyzed */ ){ - Parse *pParse = pWC->pParse; /* Parser context */ + WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */ + Parse *pParse = pWInfo->pParse; /* Parser context */ sqlite3 *db = pParse->db; /* Database connection */ WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */ Expr *pExpr = pTerm->pExpr; /* The expression of the term */ - WhereMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */ int i; /* Loop counters */ WhereClause *pOrWc; /* Breakup of pTerm into subterms */ WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */ @@ -998,7 +866,7 @@ static void exprAnalyzeOrTerm( if( pOrInfo==0 ) return; pTerm->wtFlags |= TERM_ORINFO; pOrWc = &pOrInfo->wc; - whereClauseInit(pOrWc, pWC->pParse, pMaskSet, pWC->wctrlFlags); + whereClauseInit(pOrWc, pWInfo); whereSplit(pOrWc, pExpr, TK_OR); exprAnalyzeAll(pSrc, pOrWc); if( db->mallocFailed ) return; @@ -1024,7 +892,7 @@ static void exprAnalyzeOrTerm( pOrTerm->wtFlags |= TERM_ANDINFO; pOrTerm->eOperator = WO_AND; pAndWC = &pAndInfo->wc; - whereClauseInit(pAndWC, pWC->pParse, pMaskSet, pWC->wctrlFlags); + whereClauseInit(pAndWC, pWC->pWInfo); whereSplit(pAndWC, pOrTerm->pExpr, TK_AND); exprAnalyzeAll(pSrc, pAndWC); pAndWC->pOuter = pWC; @@ -1033,7 +901,7 @@ static void exprAnalyzeOrTerm( for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){ assert( pAndTerm->pExpr ); if( allowedOp(pAndTerm->pExpr->op) ){ - b |= getMask(pMaskSet, pAndTerm->leftCursor); + b |= getMask(&pWInfo->sMaskSet, pAndTerm->leftCursor); } } } @@ -1044,10 +912,10 @@ static void exprAnalyzeOrTerm( ** corresponding TERM_VIRTUAL term */ }else{ Bitmask b; - b = getMask(pMaskSet, pOrTerm->leftCursor); + b = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor); if( pOrTerm->wtFlags & TERM_VIRTUAL ){ WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent]; - b |= getMask(pMaskSet, pOther->leftCursor); + b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor); } indexable &= b; if( (pOrTerm->eOperator & WO_EQ)==0 ){ @@ -1109,7 +977,7 @@ static void exprAnalyzeOrTerm( assert( j==1 ); continue; } - if( (chngToIN & getMask(pMaskSet, pOrTerm->leftCursor))==0 ){ + if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){ /* This term must be of the form t1.a==t2.b where t2 is in the ** chngToIN set but t1 is not. This term will be either preceeded ** or follwed by an inverted copy (t2.b==t1.a). Skip this term @@ -1128,7 +996,7 @@ static void exprAnalyzeOrTerm( ** on the second iteration */ assert( j==1 ); assert( IsPowerOfTwo(chngToIN) ); - assert( chngToIN==getMask(pMaskSet, iCursor) ); + assert( chngToIN==getMask(&pWInfo->sMaskSet, iCursor) ); break; } testcase( j==1 ); @@ -1162,8 +1030,6 @@ static void exprAnalyzeOrTerm( /* At this point, okToChngToIN is true if original pTerm satisfies ** case 1. In that case, construct a new virtual term that is ** pTerm converted into an IN operator. - ** - ** EV: R-00211-15100 */ if( okToChngToIN ){ Expr *pDup; /* A transient duplicate expression */ @@ -1177,7 +1043,7 @@ static void exprAnalyzeOrTerm( assert( pOrTerm->leftCursor==iCursor ); assert( pOrTerm->u.leftColumn==iColumn ); pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0); - pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup); + pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup); pLeft = pOrTerm->pExpr->pLeft; } assert( pLeft!=0 ); @@ -1226,6 +1092,7 @@ static void exprAnalyze( WhereClause *pWC, /* the WHERE clause */ int idxTerm /* Index of the term to be analyzed */ ){ + WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */ WhereTerm *pTerm; /* The term to be analyzed */ WhereMaskSet *pMaskSet; /* Set of table index masks */ Expr *pExpr; /* The expression to be analyzed */ @@ -1236,14 +1103,14 @@ static void exprAnalyze( int isComplete = 0; /* RHS of LIKE/GLOB ends with wildcard */ int noCase = 0; /* LIKE/GLOB distinguishes case */ int op; /* Top-level operator. pExpr->op */ - Parse *pParse = pWC->pParse; /* Parsing context */ + Parse *pParse = pWInfo->pParse; /* Parsing context */ sqlite3 *db = pParse->db; /* Database connection */ if( db->mallocFailed ){ return; } pTerm = &pWC->a[idxTerm]; - pMaskSet = pWC->pMaskSet; + pMaskSet = &pWInfo->sMaskSet; pExpr = pTerm->pExpr; assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE ); prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft); @@ -1348,6 +1215,7 @@ static void exprAnalyze( pNewExpr = sqlite3PExpr(pParse, ops[i], sqlite3ExprDup(db, pExpr->pLeft, 0), sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0); + transferJoinMarkings(pNewExpr, pExpr); idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew==0 ); exprAnalyze(pSrc, pWC, idxNew); @@ -1404,9 +1272,7 @@ static void exprAnalyze( ** inequality. To avoid this, make sure to also run the full ** LIKE on all candidate expressions by clearing the isComplete flag */ - if( c=='A'-1 ) isComplete = 0; /* EV: R-64339-08207 */ - - + if( c=='A'-1 ) isComplete = 0; c = sqlite3UpperToLower[c]; } *pC = c + 1; @@ -1417,6 +1283,7 @@ static void exprAnalyze( pNewExpr1 = sqlite3PExpr(pParse, TK_GE, sqlite3ExprAddCollateToken(pParse,pNewExpr1,&sCollSeqName), pStr1, 0); + transferJoinMarkings(pNewExpr1, pExpr); idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew1==0 ); exprAnalyze(pSrc, pWC, idxNew1); @@ -1424,6 +1291,7 @@ static void exprAnalyze( pNewExpr2 = sqlite3PExpr(pParse, TK_LT, sqlite3ExprAddCollateToken(pParse,pNewExpr2,&sCollSeqName), pStr2, 0); + transferJoinMarkings(pNewExpr2, pExpr); idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew2==0 ); exprAnalyze(pSrc, pWC, idxNew2); @@ -1473,7 +1341,7 @@ static void exprAnalyze( } #endif /* SQLITE_OMIT_VIRTUALTABLE */ -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* When sqlite_stat3 histogram data is available an operator of the ** form "x IS NOT NULL" can sometimes be evaluated more efficiently ** as "x>NULL" if x is not an INTEGER PRIMARY KEY. So construct a @@ -1487,6 +1355,7 @@ static void exprAnalyze( if( pExpr->op==TK_NOTNULL && pExpr->pLeft->op==TK_COLUMN && pExpr->pLeft->iColumn>=0 + && OptimizationEnabled(db, SQLITE_Stat3) ){ Expr *pNewExpr; Expr *pLeft = pExpr->pLeft; @@ -1512,7 +1381,7 @@ static void exprAnalyze( pNewTerm->prereqAll = pTerm->prereqAll; } } -#endif /* SQLITE_ENABLE_STAT */ +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ /* Prevent ON clause terms of a LEFT JOIN from being used to drive ** an index for tables to the left of the join. @@ -1521,11 +1390,8 @@ static void exprAnalyze( } /* -** This function searches the expression list passed as the second argument -** for an expression of type TK_COLUMN that refers to the same column and -** uses the same collation sequence as the iCol'th column of index pIdx. -** Argument iBase is the cursor number used for the table that pIdx refers -** to. +** This function searches pList for a entry that matches the iCol-th column +** of index pIdx. ** ** If such an expression is found, its index in pList->a[] is returned. If ** no expression is found, -1 is returned. @@ -1557,76 +1423,17 @@ static int findIndexCol( } /* -** This routine determines if pIdx can be used to assist in processing a -** DISTINCT qualifier. In other words, it tests whether or not using this -** index for the outer loop guarantees that rows with equal values for -** all expressions in the pDistinct list are delivered grouped together. -** -** For example, the query -** -** SELECT DISTINCT a, b, c FROM tbl WHERE a = ? -** -** can benefit from any index on columns "b" and "c". -*/ -static int isDistinctIndex( - Parse *pParse, /* Parsing context */ - WhereClause *pWC, /* The WHERE clause */ - Index *pIdx, /* The index being considered */ - int base, /* Cursor number for the table pIdx is on */ - ExprList *pDistinct, /* The DISTINCT expressions */ - int nEqCol /* Number of index columns with == */ -){ - Bitmask mask = 0; /* Mask of unaccounted for pDistinct exprs */ - int i; /* Iterator variable */ - - assert( pDistinct!=0 ); - if( pIdx->zName==0 || pDistinct->nExpr>=BMS ) return 0; - testcase( pDistinct->nExpr==BMS-1 ); - - /* Loop through all the expressions in the distinct list. If any of them - ** are not simple column references, return early. Otherwise, test if the - ** WHERE clause contains a "col=X" clause. If it does, the expression - ** can be ignored. If it does not, and the column does not belong to the - ** same table as index pIdx, return early. Finally, if there is no - ** matching "col=X" expression and the column is on the same table as pIdx, - ** set the corresponding bit in variable mask. - */ - for(i=0; i<pDistinct->nExpr; i++){ - WhereTerm *pTerm; - Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr); - if( p->op!=TK_COLUMN ) return 0; - pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0); - if( pTerm ){ - Expr *pX = pTerm->pExpr; - CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight); - CollSeq *p2 = sqlite3ExprCollSeq(pParse, p); - if( p1==p2 ) continue; - } - if( p->iTable!=base ) return 0; - mask |= (((Bitmask)1) << i); - } - - for(i=nEqCol; mask && i<pIdx->nColumn; i++){ - int iExpr = findIndexCol(pParse, pDistinct, base, pIdx, i); - if( iExpr<0 ) break; - mask &= ~(((Bitmask)1) << iExpr); - } - - return (mask==0); -} - - -/* ** Return true if the DISTINCT expression-list passed as the third argument -** is redundant. A DISTINCT list is redundant if the database contains a -** UNIQUE index that guarantees that the result of the query will be distinct -** anyway. +** is redundant. +** +** A DISTINCT list is redundant if the database contains some subset of +** columns that are unique and non-null. */ static int isDistinctRedundant( - Parse *pParse, - SrcList *pTabList, - WhereClause *pWC, - ExprList *pDistinct + Parse *pParse, /* Parsing context */ + SrcList *pTabList, /* The FROM clause */ + WhereClause *pWC, /* The WHERE clause */ + ExprList *pDistinct /* The result set that needs to be DISTINCT */ ){ Table *pTab; Index *pIdx; @@ -1663,17 +1470,17 @@ static int isDistinctRedundant( ** contain a "col=X" term are subject to a NOT NULL constraint. */ for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ - if( pIdx->onError==OE_None ) continue; - for(i=0; i<pIdx->nColumn; i++){ - int iCol = pIdx->aiColumn[i]; + if( !IsUniqueIndex(pIdx) ) continue; + for(i=0; i<pIdx->nKeyCol; i++){ + i16 iCol = pIdx->aiColumn[i]; if( 0==findTerm(pWC, iBase, iCol, ~(Bitmask)0, WO_EQ, pIdx) ){ int iIdxCol = findIndexCol(pParse, pDistinct, iBase, pIdx, i); - if( iIdxCol<0 || pTab->aCol[pIdx->aiColumn[i]].notNull==0 ){ + if( iIdxCol<0 || pTab->aCol[iCol].notNull==0 ){ break; } } } - if( i==pIdx->nColumn ){ + if( i==pIdx->nKeyCol ){ /* This index implies that the DISTINCT qualifier is redundant. */ return 1; } @@ -1682,21 +1489,12 @@ static int isDistinctRedundant( return 0; } + /* -** Prepare a crude estimate of the logarithm of the input value. -** The results need not be exact. This is only used for estimating -** the total cost of performing operations with O(logN) or O(NlogN) -** complexity. Because N is just a guess, it is no great tragedy if -** logN is a little off. +** Estimate the logarithm of the input value to base 2. */ -static double estLog(double N){ - double logN = 1; - double x = 10; - while( N>x ){ - logN += 1; - x *= 10; - } - return logN; +static LogEst estLog(LogEst N){ + return N<=10 ? 0 : sqlite3LogEst(N) - 33; } /* @@ -1705,7 +1503,7 @@ static double estLog(double N){ ** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines ** are no-ops. */ -#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_DEBUG) +#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED) static void TRACE_IDX_INPUTS(sqlite3_index_info *p){ int i; if( !sqlite3WhereTrace ) return; @@ -1737,113 +1535,13 @@ static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){ sqlite3DebugPrintf(" idxStr=%s\n", p->idxStr); sqlite3DebugPrintf(" orderByConsumed=%d\n", p->orderByConsumed); sqlite3DebugPrintf(" estimatedCost=%g\n", p->estimatedCost); + sqlite3DebugPrintf(" estimatedRows=%lld\n", p->estimatedRows); } #else #define TRACE_IDX_INPUTS(A) #define TRACE_IDX_OUTPUTS(A) #endif -/* -** Required because bestIndex() is called by bestOrClauseIndex() -*/ -static void bestIndex(WhereBestIdx*); - -/* -** This routine attempts to find an scanning strategy that can be used -** to optimize an 'OR' expression that is part of a WHERE clause. -** -** The table associated with FROM clause term pSrc may be either a -** regular B-Tree table or a virtual table. -*/ -static void bestOrClauseIndex(WhereBestIdx *p){ -#ifndef SQLITE_OMIT_OR_OPTIMIZATION - WhereClause *pWC = p->pWC; /* The WHERE clause */ - struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */ - const int iCur = pSrc->iCursor; /* The cursor of the table */ - const Bitmask maskSrc = getMask(pWC->pMaskSet, iCur); /* Bitmask for pSrc */ - WhereTerm * const pWCEnd = &pWC->a[pWC->nTerm]; /* End of pWC->a[] */ - WhereTerm *pTerm; /* A single term of the WHERE clause */ - - /* The OR-clause optimization is disallowed if the INDEXED BY or - ** NOT INDEXED clauses are used or if the WHERE_AND_ONLY bit is set. */ - if( pSrc->notIndexed || pSrc->pIndex!=0 ){ - return; - } - if( pWC->wctrlFlags & WHERE_AND_ONLY ){ - return; - } - - /* Search the WHERE clause terms for a usable WO_OR term. */ - for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){ - if( (pTerm->eOperator & WO_OR)!=0 - && ((pTerm->prereqAll & ~maskSrc) & p->notReady)==0 - && (pTerm->u.pOrInfo->indexable & maskSrc)!=0 - ){ - WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc; - WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm]; - WhereTerm *pOrTerm; - int flags = WHERE_MULTI_OR; - double rTotal = 0; - double nRow = 0; - Bitmask used = 0; - WhereBestIdx sBOI; - - sBOI = *p; - sBOI.pOrderBy = 0; - sBOI.pDistinct = 0; - sBOI.ppIdxInfo = 0; - for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){ - WHERETRACE(("... Multi-index OR testing for term %d of %d....\n", - (pOrTerm - pOrWC->a), (pTerm - pWC->a) - )); - if( (pOrTerm->eOperator& WO_AND)!=0 ){ - sBOI.pWC = &pOrTerm->u.pAndInfo->wc; - bestIndex(&sBOI); - }else if( pOrTerm->leftCursor==iCur ){ - WhereClause tempWC; - tempWC.pParse = pWC->pParse; - tempWC.pMaskSet = pWC->pMaskSet; - tempWC.pOuter = pWC; - tempWC.op = TK_AND; - tempWC.a = pOrTerm; - tempWC.wctrlFlags = 0; - tempWC.nTerm = 1; - sBOI.pWC = &tempWC; - bestIndex(&sBOI); - }else{ - continue; - } - rTotal += sBOI.cost.rCost; - nRow += sBOI.cost.plan.nRow; - used |= sBOI.cost.used; - if( rTotal>=p->cost.rCost ) break; - } - - /* If there is an ORDER BY clause, increase the scan cost to account - ** for the cost of the sort. */ - if( p->pOrderBy!=0 ){ - WHERETRACE(("... sorting increases OR cost %.9g to %.9g\n", - rTotal, rTotal+nRow*estLog(nRow))); - rTotal += nRow*estLog(nRow); - } - - /* If the cost of scanning using this OR term for optimization is - ** less than the current cost stored in pCost, replace the contents - ** of pCost. */ - WHERETRACE(("... multi-index OR cost=%.9g nrow=%.9g\n", rTotal, nRow)); - if( rTotal<p->cost.rCost ){ - p->cost.rCost = rTotal; - p->cost.used = used; - p->cost.plan.nRow = nRow; - p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0; - p->cost.plan.wsFlags = flags; - p->cost.plan.u.pTerm = pTerm; - } - } - } -#endif /* SQLITE_OMIT_OR_OPTIMIZATION */ -} - #ifndef SQLITE_OMIT_AUTOMATIC_INDEX /* ** Return TRUE if the WHERE clause term pTerm is of a form where it @@ -1859,88 +1557,13 @@ static int termCanDriveIndex( if( pTerm->leftCursor!=pSrc->iCursor ) return 0; if( (pTerm->eOperator & WO_EQ)==0 ) return 0; if( (pTerm->prereqRight & notReady)!=0 ) return 0; + if( pTerm->u.leftColumn<0 ) return 0; aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity; if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0; return 1; } #endif -#ifndef SQLITE_OMIT_AUTOMATIC_INDEX -/* -** If the query plan for pSrc specified in pCost is a full table scan -** and indexing is allows (if there is no NOT INDEXED clause) and it -** possible to construct a transient index that would perform better -** than a full table scan even when the cost of constructing the index -** is taken into account, then alter the query plan to use the -** transient index. -*/ -static void bestAutomaticIndex(WhereBestIdx *p){ - Parse *pParse = p->pParse; /* The parsing context */ - WhereClause *pWC = p->pWC; /* The WHERE clause */ - struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */ - double nTableRow; /* Rows in the input table */ - double logN; /* log(nTableRow) */ - double costTempIdx; /* per-query cost of the transient index */ - WhereTerm *pTerm; /* A single term of the WHERE clause */ - WhereTerm *pWCEnd; /* End of pWC->a[] */ - Table *pTable; /* Table tht might be indexed */ - - if( pParse->nQueryLoop<=(double)1 ){ - /* There is no point in building an automatic index for a single scan */ - return; - } - if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){ - /* Automatic indices are disabled at run-time */ - return; - } - if( (p->cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0 - && (p->cost.plan.wsFlags & WHERE_COVER_SCAN)==0 - ){ - /* We already have some kind of index in use for this query. */ - return; - } - if( pSrc->viaCoroutine ){ - /* Cannot index a co-routine */ - return; - } - if( pSrc->notIndexed ){ - /* The NOT INDEXED clause appears in the SQL. */ - return; - } - if( pSrc->isCorrelated ){ - /* The source is a correlated sub-query. No point in indexing it. */ - return; - } - - assert( pParse->nQueryLoop >= (double)1 ); - pTable = pSrc->pTab; - nTableRow = pTable->nRowEst; - logN = estLog(nTableRow); - costTempIdx = 2*logN*(nTableRow/pParse->nQueryLoop + 1); - if( costTempIdx>=p->cost.rCost ){ - /* The cost of creating the transient table would be greater than - ** doing the full table scan */ - return; - } - - /* Search for any equality comparison term */ - pWCEnd = &pWC->a[pWC->nTerm]; - for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){ - if( termCanDriveIndex(pTerm, pSrc, p->notReady) ){ - WHERETRACE(("auto-index reduces cost from %.1f to %.1f\n", - p->cost.rCost, costTempIdx)); - p->cost.rCost = costTempIdx; - p->cost.plan.nRow = logN + 1; - p->cost.plan.wsFlags = WHERE_TEMP_INDEX; - p->cost.used = pTerm->prereqRight; - break; - } - } -} -#else -# define bestAutomaticIndex(A) /* no-op */ -#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */ - #ifndef SQLITE_OMIT_AUTOMATIC_INDEX /* @@ -1955,50 +1578,61 @@ static void constructAutomaticIndex( Bitmask notReady, /* Mask of cursors that are not available */ WhereLevel *pLevel /* Write new index here */ ){ - int nColumn; /* Number of columns in the constructed index */ + int nKeyCol; /* Number of columns in the constructed index */ WhereTerm *pTerm; /* A single term of the WHERE clause */ WhereTerm *pWCEnd; /* End of pWC->a[] */ - int nByte; /* Byte of memory needed for pIdx */ Index *pIdx; /* Object describing the transient index */ Vdbe *v; /* Prepared statement under construction */ int addrInit; /* Address of the initialization bypass jump */ Table *pTable; /* The table being indexed */ - KeyInfo *pKeyinfo; /* Key information for the index */ int addrTop; /* Top of the index fill loop */ int regRecord; /* Register holding an index record */ int n; /* Column counter */ int i; /* Loop counter */ int mxBitCol; /* Maximum column in pSrc->colUsed */ CollSeq *pColl; /* Collating sequence to on a column */ + WhereLoop *pLoop; /* The Loop object */ + char *zNotUsed; /* Extra space on the end of pIdx */ Bitmask idxCols; /* Bitmap of columns used for indexing */ Bitmask extraCols; /* Bitmap of additional columns */ + u8 sentWarning = 0; /* True if a warnning has been issued */ /* Generate code to skip over the creation and initialization of the ** transient index on 2nd and subsequent iterations of the loop. */ v = pParse->pVdbe; assert( v!=0 ); - addrInit = sqlite3CodeOnce(pParse); + addrInit = sqlite3CodeOnce(pParse); VdbeCoverage(v); /* Count the number of columns that will be added to the index ** and used to match WHERE clause constraints */ - nColumn = 0; + nKeyCol = 0; pTable = pSrc->pTab; pWCEnd = &pWC->a[pWC->nTerm]; + pLoop = pLevel->pWLoop; idxCols = 0; for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){ if( termCanDriveIndex(pTerm, pSrc, notReady) ){ int iCol = pTerm->u.leftColumn; - Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol; + Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol); testcase( iCol==BMS ); testcase( iCol==BMS-1 ); + if( !sentWarning ){ + sqlite3_log(SQLITE_WARNING_AUTOINDEX, + "automatic index on %s(%s)", pTable->zName, + pTable->aCol[iCol].zName); + sentWarning = 1; + } if( (idxCols & cMask)==0 ){ - nColumn++; + if( whereLoopResize(pParse->db, pLoop, nKeyCol+1) ) return; + pLoop->aLTerm[nKeyCol++] = pTerm; idxCols |= cMask; } } } - assert( nColumn>0 ); - pLevel->plan.nEq = nColumn; + assert( nKeyCol>0 ); + pLoop->u.btree.nEq = pLoop->nLTerm = nKeyCol; + pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED + | WHERE_AUTO_INDEX; /* Count the number of additional columns needed to create a ** covering index. A "covering index" is an index that contains all @@ -2008,38 +1642,32 @@ static void constructAutomaticIndex( ** original table changes and the index and table cannot both be used ** if they go out of sync. */ - extraCols = pSrc->colUsed & (~idxCols | (((Bitmask)1)<<(BMS-1))); + extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1)); mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol; testcase( pTable->nCol==BMS-1 ); testcase( pTable->nCol==BMS-2 ); for(i=0; i<mxBitCol; i++){ - if( extraCols & (((Bitmask)1)<<i) ) nColumn++; + if( extraCols & MASKBIT(i) ) nKeyCol++; } - if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){ - nColumn += pTable->nCol - BMS + 1; + if( pSrc->colUsed & MASKBIT(BMS-1) ){ + nKeyCol += pTable->nCol - BMS + 1; } - pLevel->plan.wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WO_EQ; + pLoop->wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY; /* Construct the Index object to describe this index */ - nByte = sizeof(Index); - nByte += nColumn*sizeof(int); /* Index.aiColumn */ - nByte += nColumn*sizeof(char*); /* Index.azColl */ - nByte += nColumn; /* Index.aSortOrder */ - pIdx = sqlite3DbMallocZero(pParse->db, nByte); + pIdx = sqlite3AllocateIndexObject(pParse->db, nKeyCol+1, 0, &zNotUsed); if( pIdx==0 ) return; - pLevel->plan.u.pIdx = pIdx; - pIdx->azColl = (char**)&pIdx[1]; - pIdx->aiColumn = (int*)&pIdx->azColl[nColumn]; - pIdx->aSortOrder = (u8*)&pIdx->aiColumn[nColumn]; + pLoop->u.btree.pIndex = pIdx; pIdx->zName = "auto-index"; - pIdx->nColumn = nColumn; pIdx->pTable = pTable; n = 0; idxCols = 0; for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){ if( termCanDriveIndex(pTerm, pSrc, notReady) ){ int iCol = pTerm->u.leftColumn; - Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol; + Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol); + testcase( iCol==BMS-1 ); + testcase( iCol==BMS ); if( (idxCols & cMask)==0 ){ Expr *pX = pTerm->pExpr; idxCols |= cMask; @@ -2050,40 +1678,42 @@ static void constructAutomaticIndex( } } } - assert( (u32)n==pLevel->plan.nEq ); + assert( (u32)n==pLoop->u.btree.nEq ); /* Add additional columns needed to make the automatic index into ** a covering index */ for(i=0; i<mxBitCol; i++){ - if( extraCols & (((Bitmask)1)<<i) ){ + if( extraCols & MASKBIT(i) ){ pIdx->aiColumn[n] = i; pIdx->azColl[n] = "BINARY"; n++; } } - if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){ + if( pSrc->colUsed & MASKBIT(BMS-1) ){ for(i=BMS-1; i<pTable->nCol; i++){ pIdx->aiColumn[n] = i; pIdx->azColl[n] = "BINARY"; n++; } } - assert( n==nColumn ); + assert( n==nKeyCol ); + pIdx->aiColumn[n] = -1; + pIdx->azColl[n] = "BINARY"; /* Create the automatic index */ - pKeyinfo = sqlite3IndexKeyinfo(pParse, pIdx); assert( pLevel->iIdxCur>=0 ); - sqlite3VdbeAddOp4(v, OP_OpenAutoindex, pLevel->iIdxCur, nColumn+1, 0, - (char*)pKeyinfo, P4_KEYINFO_HANDOFF); + pLevel->iIdxCur = pParse->nTab++; + sqlite3VdbeAddOp2(v, OP_OpenAutoindex, pLevel->iIdxCur, nKeyCol+1); + sqlite3VdbeSetP4KeyInfo(pParse, pIdx); VdbeComment((v, "for %s", pTable->zName)); /* Fill the automatic index with content */ - addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); + addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur); VdbeCoverage(v); regRecord = sqlite3GetTempReg(pParse); - sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 1); + sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 0, 0, 0, 0); sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord); sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT); - sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); + sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1); VdbeCoverage(v); sqlite3VdbeChangeP5(v, SQLITE_STMTSTATUS_AUTOINDEX); sqlite3VdbeJumpHere(v, addrTop); sqlite3ReleaseTempReg(pParse, regRecord); @@ -2099,11 +1729,12 @@ static void constructAutomaticIndex( ** responsibility of the caller to eventually release the structure ** by passing the pointer returned by this function to sqlite3_free(). */ -static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ - Parse *pParse = p->pParse; - WhereClause *pWC = p->pWC; - struct SrcList_item *pSrc = p->pSrc; - ExprList *pOrderBy = p->pOrderBy; +static sqlite3_index_info *allocateIndexInfo( + Parse *pParse, + WhereClause *pWC, + struct SrcList_item *pSrc, + ExprList *pOrderBy +){ int i, j; int nTerm; struct sqlite3_index_constraint *pIdxCons; @@ -2113,8 +1744,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ int nOrderBy; sqlite3_index_info *pIdxInfo; - WHERETRACE(("Recomputing index info for %s...\n", pSrc->pTab->zName)); - /* Count the number of possible WHERE clause constraints referring ** to this virtual table */ for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ @@ -2122,7 +1751,8 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) ); testcase( pTerm->eOperator & WO_IN ); testcase( pTerm->eOperator & WO_ISNULL ); - if( pTerm->eOperator & (WO_ISNULL) ) continue; + testcase( pTerm->eOperator & WO_ALL ); + if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV))==0 ) continue; if( pTerm->wtFlags & TERM_VNULL ) continue; nTerm++; } @@ -2150,7 +1780,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ + sizeof(*pIdxOrderBy)*nOrderBy ); if( pIdxInfo==0 ){ sqlite3ErrorMsg(pParse, "out of memory"); - /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */ return 0; } @@ -2175,7 +1804,8 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ assert( IsPowerOfTwo(pTerm->eOperator & ~WO_EQUIV) ); testcase( pTerm->eOperator & WO_IN ); testcase( pTerm->eOperator & WO_ISNULL ); - if( pTerm->eOperator & (WO_ISNULL) ) continue; + testcase( pTerm->eOperator & WO_ALL ); + if( (pTerm->eOperator & ~(WO_ISNULL|WO_EQUIV))==0 ) continue; if( pTerm->wtFlags & TERM_VNULL ) continue; pIdxCons[j].iColumn = pTerm->u.leftColumn; pIdxCons[j].iTermOffset = i; @@ -2206,8 +1836,8 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ /* ** The table object reference passed as the second argument to this function ** must represent a virtual table. This function invokes the xBestIndex() -** method of the virtual table with the sqlite3_index_info pointer passed -** as the argument. +** method of the virtual table with the sqlite3_index_info object that +** comes in as the 3rd argument to this function. ** ** If an error occurs, pParse is populated with an error message and a ** non-zero value is returned. Otherwise, 0 is returned and the output @@ -2222,7 +1852,6 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){ int i; int rc; - WHERETRACE(("xBestIndex for %s\n", pTab->zName)); TRACE_IDX_INPUTS(p); rc = pVtab->pModule->xBestIndex(pVtab, p); TRACE_IDX_OUTPUTS(p); @@ -2248,209 +1877,10 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){ return pParse->nErr; } +#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */ -/* -** Compute the best index for a virtual table. -** -** The best index is computed by the xBestIndex method of the virtual -** table module. This routine is really just a wrapper that sets up -** the sqlite3_index_info structure that is used to communicate with -** xBestIndex. -** -** In a join, this routine might be called multiple times for the -** same virtual table. The sqlite3_index_info structure is created -** and initialized on the first invocation and reused on all subsequent -** invocations. The sqlite3_index_info structure is also used when -** code is generated to access the virtual table. The whereInfoDelete() -** routine takes care of freeing the sqlite3_index_info structure after -** everybody has finished with it. -*/ -static void bestVirtualIndex(WhereBestIdx *p){ - Parse *pParse = p->pParse; /* The parsing context */ - WhereClause *pWC = p->pWC; /* The WHERE clause */ - struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */ - Table *pTab = pSrc->pTab; - sqlite3_index_info *pIdxInfo; - struct sqlite3_index_constraint *pIdxCons; - struct sqlite3_index_constraint_usage *pUsage; - WhereTerm *pTerm; - int i, j; - int nOrderBy; - int bAllowIN; /* Allow IN optimizations */ - double rCost; - - /* Make sure wsFlags is initialized to some sane value. Otherwise, if the - ** malloc in allocateIndexInfo() fails and this function returns leaving - ** wsFlags in an uninitialized state, the caller may behave unpredictably. - */ - memset(&p->cost, 0, sizeof(p->cost)); - p->cost.plan.wsFlags = WHERE_VIRTUALTABLE; - - /* If the sqlite3_index_info structure has not been previously - ** allocated and initialized, then allocate and initialize it now. - */ - pIdxInfo = *p->ppIdxInfo; - if( pIdxInfo==0 ){ - *p->ppIdxInfo = pIdxInfo = allocateIndexInfo(p); - } - if( pIdxInfo==0 ){ - return; - } - - /* At this point, the sqlite3_index_info structure that pIdxInfo points - ** to will have been initialized, either during the current invocation or - ** during some prior invocation. Now we just have to customize the - ** details of pIdxInfo for the current invocation and pass it to - ** xBestIndex. - */ - - /* The module name must be defined. Also, by this point there must - ** be a pointer to an sqlite3_vtab structure. Otherwise - ** sqlite3ViewGetColumnNames() would have picked up the error. - */ - assert( pTab->azModuleArg && pTab->azModuleArg[0] ); - assert( sqlite3GetVTable(pParse->db, pTab) ); - - /* Try once or twice. On the first attempt, allow IN optimizations. - ** If an IN optimization is accepted by the virtual table xBestIndex - ** method, but the pInfo->aConstrainUsage.omit flag is not set, then - ** the query will not work because it might allow duplicate rows in - ** output. In that case, run the xBestIndex method a second time - ** without the IN constraints. Usually this loop only runs once. - ** The loop will exit using a "break" statement. - */ - for(bAllowIN=1; 1; bAllowIN--){ - assert( bAllowIN==0 || bAllowIN==1 ); - - /* Set the aConstraint[].usable fields and initialize all - ** output variables to zero. - ** - ** aConstraint[].usable is true for constraints where the right-hand - ** side contains only references to tables to the left of the current - ** table. In other words, if the constraint is of the form: - ** - ** column = expr - ** - ** and we are evaluating a join, then the constraint on column is - ** only valid if all tables referenced in expr occur to the left - ** of the table containing column. - ** - ** The aConstraints[] array contains entries for all constraints - ** on the current table. That way we only have to compute it once - ** even though we might try to pick the best index multiple times. - ** For each attempt at picking an index, the order of tables in the - ** join might be different so we have to recompute the usable flag - ** each time. - */ - pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; - pUsage = pIdxInfo->aConstraintUsage; - for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ - j = pIdxCons->iTermOffset; - pTerm = &pWC->a[j]; - if( (pTerm->prereqRight&p->notReady)==0 - && (bAllowIN || (pTerm->eOperator & WO_IN)==0) - ){ - pIdxCons->usable = 1; - }else{ - pIdxCons->usable = 0; - } - } - memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint); - if( pIdxInfo->needToFreeIdxStr ){ - sqlite3_free(pIdxInfo->idxStr); - } - pIdxInfo->idxStr = 0; - pIdxInfo->idxNum = 0; - pIdxInfo->needToFreeIdxStr = 0; - pIdxInfo->orderByConsumed = 0; - /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */ - pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2); - nOrderBy = pIdxInfo->nOrderBy; - if( !p->pOrderBy ){ - pIdxInfo->nOrderBy = 0; - } - - if( vtabBestIndex(pParse, pTab, pIdxInfo) ){ - return; - } - - pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; - for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ - if( pUsage[i].argvIndex>0 ){ - j = pIdxCons->iTermOffset; - pTerm = &pWC->a[j]; - p->cost.used |= pTerm->prereqRight; - if( (pTerm->eOperator & WO_IN)!=0 ){ - if( pUsage[i].omit==0 ){ - /* Do not attempt to use an IN constraint if the virtual table - ** says that the equivalent EQ constraint cannot be safely omitted. - ** If we do attempt to use such a constraint, some rows might be - ** repeated in the output. */ - break; - } - /* A virtual table that is constrained by an IN clause may not - ** consume the ORDER BY clause because (1) the order of IN terms - ** is not necessarily related to the order of output terms and - ** (2) Multiple outputs from a single IN value will not merge - ** together. */ - pIdxInfo->orderByConsumed = 0; - } - } - } - if( i>=pIdxInfo->nConstraint ) break; - } - - /* The orderByConsumed signal is only valid if all outer loops collectively - ** generate just a single row of output. - */ - if( pIdxInfo->orderByConsumed ){ - for(i=0; i<p->i; i++){ - if( (p->aLevel[i].plan.wsFlags & WHERE_UNIQUE)==0 ){ - pIdxInfo->orderByConsumed = 0; - } - } - } - - /* If there is an ORDER BY clause, and the selected virtual table index - ** does not satisfy it, increase the cost of the scan accordingly. This - ** matches the processing for non-virtual tables in bestBtreeIndex(). - */ - rCost = pIdxInfo->estimatedCost; - if( p->pOrderBy && pIdxInfo->orderByConsumed==0 ){ - rCost += estLog(rCost)*rCost; - } - - /* The cost is not allowed to be larger than SQLITE_BIG_DBL (the - ** inital value of lowestCost in this loop. If it is, then the - ** (cost<lowestCost) test below will never be true. - ** - ** Use "(double)2" instead of "2.0" in case OMIT_FLOATING_POINT - ** is defined. - */ - if( (SQLITE_BIG_DBL/((double)2))<rCost ){ - p->cost.rCost = (SQLITE_BIG_DBL/((double)2)); - }else{ - p->cost.rCost = rCost; - } - p->cost.plan.u.pVtabIdx = pIdxInfo; - if( pIdxInfo->orderByConsumed ){ - p->cost.plan.wsFlags |= WHERE_ORDERED; - p->cost.plan.nOBSat = nOrderBy; - }else{ - p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0; - } - p->cost.plan.nEq = 0; - pIdxInfo->nOrderBy = nOrderBy; - - /* Try to find a more efficient access pattern by using multiple indexes - ** to optimize an OR expression within the WHERE clause. - */ - bestOrClauseIndex(p); -} -#endif /* SQLITE_OMIT_VIRTUALTABLE */ - -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* ** Estimate the location of a particular key among all keys in an ** index. Store the results in aStat as follows: @@ -2460,140 +1890,76 @@ static void bestVirtualIndex(WhereBestIdx *p){ ** ** Return SQLITE_OK on success. */ -static int whereKeyStats( +static void whereKeyStats( Parse *pParse, /* Database connection */ Index *pIdx, /* Index to consider domain of */ - sqlite3_value *pVal, /* Value to consider */ + UnpackedRecord *pRec, /* Vector of values to consider */ int roundUp, /* Round up if true. Round down if false */ tRowcnt *aStat /* OUT: stats written here */ ){ - tRowcnt n; - IndexSample *aSample; - int i, eType; - int isEq = 0; - i64 v; - double r, rS; - - assert( roundUp==0 || roundUp==1 ); + IndexSample *aSample = pIdx->aSample; + int iCol; /* Index of required stats in anEq[] etc. */ + int iMin = 0; /* Smallest sample not yet tested */ + int i = pIdx->nSample; /* Smallest sample larger than or equal to pRec */ + int iTest; /* Next sample to test */ + int res; /* Result of comparison operation */ + +#ifndef SQLITE_DEBUG + UNUSED_PARAMETER( pParse ); +#endif + assert( pRec!=0 ); + iCol = pRec->nField - 1; assert( pIdx->nSample>0 ); - if( pVal==0 ) return SQLITE_ERROR; - n = pIdx->aiRowEst[0]; - aSample = pIdx->aSample; - eType = sqlite3_value_type(pVal); - - if( eType==SQLITE_INTEGER ){ - v = sqlite3_value_int64(pVal); - r = (i64)v; - for(i=0; i<pIdx->nSample; i++){ - if( aSample[i].eType==SQLITE_NULL ) continue; - if( aSample[i].eType>=SQLITE_TEXT ) break; - if( aSample[i].eType==SQLITE_INTEGER ){ - if( aSample[i].u.i>=v ){ - isEq = aSample[i].u.i==v; - break; - } - }else{ - assert( aSample[i].eType==SQLITE_FLOAT ); - if( aSample[i].u.r>=r ){ - isEq = aSample[i].u.r==r; - break; - } - } - } - }else if( eType==SQLITE_FLOAT ){ - r = sqlite3_value_double(pVal); - for(i=0; i<pIdx->nSample; i++){ - if( aSample[i].eType==SQLITE_NULL ) continue; - if( aSample[i].eType>=SQLITE_TEXT ) break; - if( aSample[i].eType==SQLITE_FLOAT ){ - rS = aSample[i].u.r; - }else{ - rS = aSample[i].u.i; - } - if( rS>=r ){ - isEq = rS==r; - break; - } + assert( pRec->nField>0 && iCol<pIdx->nSampleCol ); + do{ + iTest = (iMin+i)/2; + res = sqlite3VdbeRecordCompare(aSample[iTest].n, aSample[iTest].p, pRec, 0); + if( res<0 ){ + iMin = iTest+1; + }else{ + i = iTest; } - }else if( eType==SQLITE_NULL ){ - i = 0; - if( aSample[0].eType==SQLITE_NULL ) isEq = 1; + }while( res && iMin<i ); + +#ifdef SQLITE_DEBUG + /* The following assert statements check that the binary search code + ** above found the right answer. This block serves no purpose other + ** than to invoke the asserts. */ + if( res==0 ){ + /* If (res==0) is true, then sample $i must be equal to pRec */ + assert( i<pIdx->nSample ); + assert( 0==sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec, 0) + || pParse->db->mallocFailed ); }else{ - assert( eType==SQLITE_TEXT || eType==SQLITE_BLOB ); - for(i=0; i<pIdx->nSample; i++){ - if( aSample[i].eType==SQLITE_TEXT || aSample[i].eType==SQLITE_BLOB ){ - break; - } - } - if( i<pIdx->nSample ){ - sqlite3 *db = pParse->db; - CollSeq *pColl; - const u8 *z; - if( eType==SQLITE_BLOB ){ - z = (const u8 *)sqlite3_value_blob(pVal); - pColl = db->pDfltColl; - assert( pColl->enc==SQLITE_UTF8 ); - }else{ - pColl = sqlite3GetCollSeq(pParse, SQLITE_UTF8, 0, *pIdx->azColl); - if( pColl==0 ){ - return SQLITE_ERROR; - } - z = (const u8 *)sqlite3ValueText(pVal, pColl->enc); - if( !z ){ - return SQLITE_NOMEM; - } - assert( z && pColl && pColl->xCmp ); - } - n = sqlite3ValueBytes(pVal, pColl->enc); - - for(; i<pIdx->nSample; i++){ - int c; - int eSampletype = aSample[i].eType; - if( eSampletype<eType ) continue; - if( eSampletype!=eType ) break; -#ifndef SQLITE_OMIT_UTF16 - if( pColl->enc!=SQLITE_UTF8 ){ - int nSample; - char *zSample = sqlite3Utf8to16( - db, pColl->enc, aSample[i].u.z, aSample[i].nByte, &nSample - ); - if( !zSample ){ - assert( db->mallocFailed ); - return SQLITE_NOMEM; - } - c = pColl->xCmp(pColl->pUser, nSample, zSample, n, z); - sqlite3DbFree(db, zSample); - }else -#endif - { - c = pColl->xCmp(pColl->pUser, aSample[i].nByte, aSample[i].u.z, n, z); - } - if( c>=0 ){ - if( c==0 ) isEq = 1; - break; - } - } - } + /* Otherwise, pRec must be smaller than sample $i and larger than + ** sample ($i-1). */ + assert( i==pIdx->nSample + || sqlite3VdbeRecordCompare(aSample[i].n, aSample[i].p, pRec, 0)>0 + || pParse->db->mallocFailed ); + assert( i==0 + || sqlite3VdbeRecordCompare(aSample[i-1].n, aSample[i-1].p, pRec, 0)<0 + || pParse->db->mallocFailed ); } +#endif /* ifdef SQLITE_DEBUG */ /* At this point, aSample[i] is the first sample that is greater than ** or equal to pVal. Or if i==pIdx->nSample, then all samples are less - ** than pVal. If aSample[i]==pVal, then isEq==1. + ** than pVal. If aSample[i]==pVal, then res==0. */ - if( isEq ){ - assert( i<pIdx->nSample ); - aStat[0] = aSample[i].nLt; - aStat[1] = aSample[i].nEq; + if( res==0 ){ + aStat[0] = aSample[i].anLt[iCol]; + aStat[1] = aSample[i].anEq[iCol]; }else{ tRowcnt iLower, iUpper, iGap; if( i==0 ){ iLower = 0; - iUpper = aSample[0].nLt; + iUpper = aSample[0].anLt[iCol]; }else{ - iUpper = i>=pIdx->nSample ? n : aSample[i].nLt; - iLower = aSample[i-1].nEq + aSample[i-1].nLt; + i64 nRow0 = sqlite3LogEstToInt(pIdx->aiRowLogEst[0]); + iUpper = i>=pIdx->nSample ? nRow0 : aSample[i].anLt[iCol]; + iLower = aSample[i-1].anEq[iCol] + aSample[i-1].anLt[iCol]; } - aStat[1] = pIdx->avgEq; + aStat[1] = pIdx->aAvgEq[iCol]; if( iLower>=iUpper ){ iGap = 0; }else{ @@ -2606,44 +1972,140 @@ static int whereKeyStats( } aStat[0] = iLower + iGap; } - return SQLITE_OK; } -#endif /* SQLITE_ENABLE_STAT3 */ +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ /* -** If expression pExpr represents a literal value, set *pp to point to -** an sqlite3_value structure containing the same value, with affinity -** aff applied to it, before returning. It is the responsibility of the -** caller to eventually release this structure by passing it to -** sqlite3ValueFree(). -** -** If the current parse is a recompile (sqlite3Reprepare()) and pExpr -** is an SQL variable that currently has a non-NULL value bound to it, -** create an sqlite3_value structure containing this value, again with -** affinity aff applied to it, instead. -** -** If neither of the above apply, set *pp to NULL. -** -** If an error occurs, return an error code. Otherwise, SQLITE_OK. +** If it is not NULL, pTerm is a term that provides an upper or lower +** bound on a range scan. Without considering pTerm, it is estimated +** that the scan will visit nNew rows. This function returns the number +** estimated to be visited after taking pTerm into account. +** +** If the user explicitly specified a likelihood() value for this term, +** then the return value is the likelihood multiplied by the number of +** input rows. Otherwise, this function assumes that an "IS NOT NULL" term +** has a likelihood of 0.50, and any other term a likelihood of 0.25. +*/ +static LogEst whereRangeAdjust(WhereTerm *pTerm, LogEst nNew){ + LogEst nRet = nNew; + if( pTerm ){ + if( pTerm->truthProb<=0 ){ + nRet += pTerm->truthProb; + }else if( (pTerm->wtFlags & TERM_VNULL)==0 ){ + nRet -= 20; assert( 20==sqlite3LogEst(4) ); + } + } + return nRet; +} + +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 +/* +** This function is called to estimate the number of rows visited by a +** range-scan on a skip-scan index. For example: +** +** CREATE INDEX i1 ON t1(a, b, c); +** SELECT * FROM t1 WHERE a=? AND c BETWEEN ? AND ?; +** +** Value pLoop->nOut is currently set to the estimated number of rows +** visited for scanning (a=? AND b=?). This function reduces that estimate +** by some factor to account for the (c BETWEEN ? AND ?) expression based +** on the stat4 data for the index. this scan will be peformed multiple +** times (once for each (a,b) combination that matches a=?) is dealt with +** by the caller. +** +** It does this by scanning through all stat4 samples, comparing values +** extracted from pLower and pUpper with the corresponding column in each +** sample. If L and U are the number of samples found to be less than or +** equal to the values extracted from pLower and pUpper respectively, and +** N is the total number of samples, the pLoop->nOut value is adjusted +** as follows: +** +** nOut = nOut * ( min(U - L, 1) / N ) +** +** If pLower is NULL, or a value cannot be extracted from the term, L is +** set to zero. If pUpper is NULL, or a value cannot be extracted from it, +** U is set to N. +** +** Normally, this function sets *pbDone to 1 before returning. However, +** if no value can be extracted from either pLower or pUpper (and so the +** estimate of the number of rows delivered remains unchanged), *pbDone +** is left as is. +** +** If an error occurs, an SQLite error code is returned. Otherwise, +** SQLITE_OK. */ -#ifdef SQLITE_ENABLE_STAT3 -static int valueFromExpr( - Parse *pParse, - Expr *pExpr, - u8 aff, - sqlite3_value **pp +static int whereRangeSkipScanEst( + Parse *pParse, /* Parsing & code generating context */ + WhereTerm *pLower, /* Lower bound on the range. ex: "x>123" Might be NULL */ + WhereTerm *pUpper, /* Upper bound on the range. ex: "x<455" Might be NULL */ + WhereLoop *pLoop, /* Update the .nOut value of this loop */ + int *pbDone /* Set to true if at least one expr. value extracted */ ){ - if( pExpr->op==TK_VARIABLE - || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE) - ){ - int iVar = pExpr->iColumn; - sqlite3VdbeSetVarmask(pParse->pVdbe, iVar); - *pp = sqlite3VdbeGetValue(pParse->pReprepare, iVar, aff); - return SQLITE_OK; + Index *p = pLoop->u.btree.pIndex; + int nEq = pLoop->u.btree.nEq; + sqlite3 *db = pParse->db; + int nLower = -1; + int nUpper = p->nSample+1; + int rc = SQLITE_OK; + int iCol = p->aiColumn[nEq]; + u8 aff = iCol>=0 ? p->pTable->aCol[iCol].affinity : SQLITE_AFF_INTEGER; + CollSeq *pColl; + + sqlite3_value *p1 = 0; /* Value extracted from pLower */ + sqlite3_value *p2 = 0; /* Value extracted from pUpper */ + sqlite3_value *pVal = 0; /* Value extracted from record */ + + pColl = sqlite3LocateCollSeq(pParse, p->azColl[nEq]); + if( pLower ){ + rc = sqlite3Stat4ValueFromExpr(pParse, pLower->pExpr->pRight, aff, &p1); + nLower = 0; + } + if( pUpper && rc==SQLITE_OK ){ + rc = sqlite3Stat4ValueFromExpr(pParse, pUpper->pExpr->pRight, aff, &p2); + nUpper = p2 ? 0 : p->nSample; + } + + if( p1 || p2 ){ + int i; + int nDiff; + for(i=0; rc==SQLITE_OK && i<p->nSample; i++){ + rc = sqlite3Stat4Column(db, p->aSample[i].p, p->aSample[i].n, nEq, &pVal); + if( rc==SQLITE_OK && p1 ){ + int res = sqlite3MemCompare(p1, pVal, pColl); + if( res>=0 ) nLower++; + } + if( rc==SQLITE_OK && p2 ){ + int res = sqlite3MemCompare(p2, pVal, pColl); + if( res>=0 ) nUpper++; + } + } + nDiff = (nUpper - nLower); + if( nDiff<=0 ) nDiff = 1; + + /* If there is both an upper and lower bound specified, and the + ** comparisons indicate that they are close together, use the fallback + ** method (assume that the scan visits 1/64 of the rows) for estimating + ** the number of rows visited. Otherwise, estimate the number of rows + ** using the method described in the header comment for this function. */ + if( nDiff!=1 || pUpper==0 || pLower==0 ){ + int nAdjust = (sqlite3LogEst(p->nSample) - sqlite3LogEst(nDiff)); + pLoop->nOut -= nAdjust; + *pbDone = 1; + WHERETRACE(0x10, ("range skip-scan regions: %u..%u adjust=%d est=%d\n", + nLower, nUpper, nAdjust*-1, pLoop->nOut)); + } + + }else{ + assert( *pbDone==0 ); } - return sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, aff, pp); + + sqlite3ValueFree(p1); + sqlite3ValueFree(p2); + sqlite3ValueFree(pVal); + + return rc; } -#endif +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ /* ** This function is used to estimate the number of rows that will be visited @@ -2660,97 +2122,167 @@ static int valueFromExpr( ** If either of the upper or lower bound is not present, then NULL is passed in ** place of the corresponding WhereTerm. ** -** The nEq parameter is passed the index of the index column subject to the -** range constraint. Or, equivalently, the number of equality constraints -** optimized by the proposed index scan. For example, assuming index p is -** on t1(a, b), and the SQL query is: +** The value in (pBuilder->pNew->u.btree.nEq) is the index of the index +** column subject to the range constraint. Or, equivalently, the number of +** equality constraints optimized by the proposed index scan. For example, +** assuming index p is on t1(a, b), and the SQL query is: ** ** ... FROM t1 WHERE a = ? AND b > ? AND b < ? ... ** -** then nEq should be passed the value 1 (as the range restricted column, -** b, is the second left-most column of the index). Or, if the query is: +** then nEq is set to 1 (as the range restricted column, b, is the second +** left-most column of the index). Or, if the query is: ** ** ... FROM t1 WHERE a > ? AND a < ? ... ** -** then nEq should be passed 0. -** -** The returned value is an integer divisor to reduce the estimated -** search space. A return value of 1 means that range constraints are -** no help at all. A return value of 2 means range constraints are -** expected to reduce the search space by half. And so forth... -** -** In the absence of sqlite_stat3 ANALYZE data, each range inequality -** reduces the search space by a factor of 4. Hence a single constraint (x>?) -** results in a return of 4 and a range constraint (x>? AND x<?) results -** in a return of 16. +** then nEq is set to 0. +** +** When this function is called, *pnOut is set to the sqlite3LogEst() of the +** number of rows that the index scan is expected to visit without +** considering the range constraints. If nEq is 0, this is the number of +** rows in the index. Assuming no error occurs, *pnOut is adjusted (reduced) +** to account for the range contraints pLower and pUpper. +** +** In the absence of sqlite_stat4 ANALYZE data, or if such data cannot be +** used, a single range inequality reduces the search space by a factor of 4. +** and a pair of constraints (x>? AND x<?) reduces the expected number of +** rows visited by a factor of 64. */ static int whereRangeScanEst( Parse *pParse, /* Parsing & code generating context */ - Index *p, /* The index containing the range-compared column; "x" */ - int nEq, /* index into p->aCol[] of the range-compared column */ + WhereLoopBuilder *pBuilder, WhereTerm *pLower, /* Lower bound on the range. ex: "x>123" Might be NULL */ WhereTerm *pUpper, /* Upper bound on the range. ex: "x<455" Might be NULL */ - double *pRangeDiv /* OUT: Reduce search space by this divisor */ + WhereLoop *pLoop /* Modify the .nOut and maybe .rRun fields */ ){ int rc = SQLITE_OK; + int nOut = pLoop->nOut; + LogEst nNew; -#ifdef SQLITE_ENABLE_STAT3 - - if( nEq==0 && p->nSample ){ - sqlite3_value *pRangeVal; - tRowcnt iLower = 0; - tRowcnt iUpper = p->aiRowEst[0]; - tRowcnt a[2]; - u8 aff = p->pTable->aCol[p->aiColumn[0]].affinity; - - if( pLower ){ - Expr *pExpr = pLower->pExpr->pRight; - rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal); - assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 ); - if( rc==SQLITE_OK - && whereKeyStats(pParse, p, pRangeVal, 0, a)==SQLITE_OK - ){ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + Index *p = pLoop->u.btree.pIndex; + int nEq = pLoop->u.btree.nEq; + + if( p->nSample>0 + && nEq<p->nSampleCol + && OptimizationEnabled(pParse->db, SQLITE_Stat3) + ){ + if( nEq==pBuilder->nRecValid ){ + UnpackedRecord *pRec = pBuilder->pRec; + tRowcnt a[2]; + u8 aff; + + /* Variable iLower will be set to the estimate of the number of rows in + ** the index that are less than the lower bound of the range query. The + ** lower bound being the concatenation of $P and $L, where $P is the + ** key-prefix formed by the nEq values matched against the nEq left-most + ** columns of the index, and $L is the value in pLower. + ** + ** Or, if pLower is NULL or $L cannot be extracted from it (because it + ** is not a simple variable or literal value), the lower bound of the + ** range is $P. Due to a quirk in the way whereKeyStats() works, even + ** if $L is available, whereKeyStats() is called for both ($P) and + ** ($P:$L) and the larger of the two returned values used. + ** + ** Similarly, iUpper is to be set to the estimate of the number of rows + ** less than the upper bound of the range query. Where the upper bound + ** is either ($P) or ($P:$U). Again, even if $U is available, both values + ** of iUpper are requested of whereKeyStats() and the smaller used. + */ + tRowcnt iLower; + tRowcnt iUpper; + + if( nEq==p->nKeyCol ){ + aff = SQLITE_AFF_INTEGER; + }else{ + aff = p->pTable->aCol[p->aiColumn[nEq]].affinity; + } + /* Determine iLower and iUpper using ($P) only. */ + if( nEq==0 ){ + iLower = 0; + iUpper = sqlite3LogEstToInt(p->aiRowLogEst[0]); + }else{ + /* Note: this call could be optimized away - since the same values must + ** have been requested when testing key $P in whereEqualScanEst(). */ + whereKeyStats(pParse, p, pRec, 0, a); iLower = a[0]; - if( (pLower->eOperator & WO_GT)!=0 ) iLower += a[1]; + iUpper = a[0] + a[1]; } - sqlite3ValueFree(pRangeVal); - } - if( rc==SQLITE_OK && pUpper ){ - Expr *pExpr = pUpper->pExpr->pRight; - rc = valueFromExpr(pParse, pExpr, aff, &pRangeVal); - assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 ); - if( rc==SQLITE_OK - && whereKeyStats(pParse, p, pRangeVal, 1, a)==SQLITE_OK - ){ - iUpper = a[0]; - if( (pUpper->eOperator & WO_LE)!=0 ) iUpper += a[1]; + + /* If possible, improve on the iLower estimate using ($P:$L). */ + if( pLower ){ + int bOk; /* True if value is extracted from pExpr */ + Expr *pExpr = pLower->pExpr->pRight; + assert( (pLower->eOperator & (WO_GT|WO_GE))!=0 ); + rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); + if( rc==SQLITE_OK && bOk ){ + tRowcnt iNew; + whereKeyStats(pParse, p, pRec, 0, a); + iNew = a[0] + ((pLower->eOperator & WO_GT) ? a[1] : 0); + if( iNew>iLower ) iLower = iNew; + nOut--; + } } - sqlite3ValueFree(pRangeVal); - } - if( rc==SQLITE_OK ){ - if( iUpper<=iLower ){ - *pRangeDiv = (double)p->aiRowEst[0]; - }else{ - *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower); + + /* If possible, improve on the iUpper estimate using ($P:$U). */ + if( pUpper ){ + int bOk; /* True if value is extracted from pExpr */ + Expr *pExpr = pUpper->pExpr->pRight; + assert( (pUpper->eOperator & (WO_LT|WO_LE))!=0 ); + rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq, &bOk); + if( rc==SQLITE_OK && bOk ){ + tRowcnt iNew; + whereKeyStats(pParse, p, pRec, 1, a); + iNew = a[0] + ((pUpper->eOperator & WO_LE) ? a[1] : 0); + if( iNew<iUpper ) iUpper = iNew; + nOut--; + } + } + + pBuilder->pRec = pRec; + if( rc==SQLITE_OK ){ + if( iUpper>iLower ){ + nNew = sqlite3LogEst(iUpper - iLower); + }else{ + nNew = 10; assert( 10==sqlite3LogEst(2) ); + } + if( nNew<nOut ){ + nOut = nNew; + } + pLoop->nOut = (LogEst)nOut; + WHERETRACE(0x10, ("range scan regions: %u..%u est=%d\n", + (u32)iLower, (u32)iUpper, nOut)); + return SQLITE_OK; } - WHERETRACE(("range scan regions: %u..%u div=%g\n", - (u32)iLower, (u32)iUpper, *pRangeDiv)); - return SQLITE_OK; + }else{ + int bDone = 0; + rc = whereRangeSkipScanEst(pParse, pLower, pUpper, pLoop, &bDone); + if( bDone ) return rc; } } #else UNUSED_PARAMETER(pParse); - UNUSED_PARAMETER(p); - UNUSED_PARAMETER(nEq); + UNUSED_PARAMETER(pBuilder); #endif assert( pLower || pUpper ); - *pRangeDiv = (double)1; - if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4; - if( pUpper ) *pRangeDiv *= (double)4; + assert( pUpper==0 || (pUpper->wtFlags & TERM_VNULL)==0 ); + nNew = whereRangeAdjust(pLower, nOut); + nNew = whereRangeAdjust(pUpper, nNew); + + /* TUNING: If there is both an upper and lower limit, assume the range is + ** reduced by an additional 75%. This means that, by default, an open-ended + ** range query (e.g. col > ?) is assumed to match 1/4 of the rows in the + ** index. While a closed range (e.g. col BETWEEN ? AND ?) is estimated to + ** match 1/64 of the index. */ + if( pLower && pUpper ) nNew -= 20; + + nOut -= (pLower!=0) + (pUpper!=0); + if( nNew<10 ) nNew = 10; + if( nNew<nOut ) nOut = nNew; + pLoop->nOut = (LogEst)nOut; return rc; } -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* ** Estimate the number of rows that will be returned based on ** an equality constraint x=VALUE and where that VALUE occurs in @@ -2770,37 +2302,53 @@ static int whereRangeScanEst( */ static int whereEqualScanEst( Parse *pParse, /* Parsing & code generating context */ - Index *p, /* The index whose left-most column is pTerm */ + WhereLoopBuilder *pBuilder, Expr *pExpr, /* Expression for VALUE in the x=VALUE constraint */ - double *pnRow /* Write the revised row estimate here */ + tRowcnt *pnRow /* Write the revised row estimate here */ ){ - sqlite3_value *pRhs = 0; /* VALUE on right-hand side of pTerm */ + Index *p = pBuilder->pNew->u.btree.pIndex; + int nEq = pBuilder->pNew->u.btree.nEq; + UnpackedRecord *pRec = pBuilder->pRec; u8 aff; /* Column affinity */ int rc; /* Subfunction return code */ tRowcnt a[2]; /* Statistics */ + int bOk; + assert( nEq>=1 ); + assert( nEq<=p->nColumn ); assert( p->aSample!=0 ); assert( p->nSample>0 ); - aff = p->pTable->aCol[p->aiColumn[0]].affinity; - if( pExpr ){ - rc = valueFromExpr(pParse, pExpr, aff, &pRhs); - if( rc ) goto whereEqualScanEst_cancel; - }else{ - pRhs = sqlite3ValueNew(pParse->db); + assert( pBuilder->nRecValid<nEq ); + + /* If values are not available for all fields of the index to the left + ** of this one, no estimate can be made. Return SQLITE_NOTFOUND. */ + if( pBuilder->nRecValid<(nEq-1) ){ + return SQLITE_NOTFOUND; } - if( pRhs==0 ) return SQLITE_NOTFOUND; - rc = whereKeyStats(pParse, p, pRhs, 0, a); - if( rc==SQLITE_OK ){ - WHERETRACE(("equality scan regions: %d\n", (int)a[1])); - *pnRow = a[1]; + + /* This is an optimization only. The call to sqlite3Stat4ProbeSetValue() + ** below would return the same value. */ + if( nEq>=p->nColumn ){ + *pnRow = 1; + return SQLITE_OK; } -whereEqualScanEst_cancel: - sqlite3ValueFree(pRhs); + + aff = p->pTable->aCol[p->aiColumn[nEq-1]].affinity; + rc = sqlite3Stat4ProbeSetValue(pParse, p, &pRec, pExpr, aff, nEq-1, &bOk); + pBuilder->pRec = pRec; + if( rc!=SQLITE_OK ) return rc; + if( bOk==0 ) return SQLITE_NOTFOUND; + pBuilder->nRecValid = nEq; + + whereKeyStats(pParse, p, pRec, 0, a); + WHERETRACE(0x10,("equality scan regions: %d\n", (int)a[1])); + *pnRow = a[1]; + return rc; } -#endif /* defined(SQLITE_ENABLE_STAT3) */ +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ -#ifdef SQLITE_ENABLE_STAT3 +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* ** Estimate the number of rows that will be returned based on ** an IN constraint where the right-hand side of the IN operator @@ -2819,902 +2367,35 @@ whereEqualScanEst_cancel: */ static int whereInScanEst( Parse *pParse, /* Parsing & code generating context */ - Index *p, /* The index whose left-most column is pTerm */ + WhereLoopBuilder *pBuilder, ExprList *pList, /* The value list on the RHS of "x IN (v1,v2,v3,...)" */ - double *pnRow /* Write the revised row estimate here */ + tRowcnt *pnRow /* Write the revised row estimate here */ ){ - int rc = SQLITE_OK; /* Subfunction return code */ - double nEst; /* Number of rows for a single term */ - double nRowEst = (double)0; /* New estimate of the number of rows */ - int i; /* Loop counter */ + Index *p = pBuilder->pNew->u.btree.pIndex; + i64 nRow0 = sqlite3LogEstToInt(p->aiRowLogEst[0]); + int nRecValid = pBuilder->nRecValid; + int rc = SQLITE_OK; /* Subfunction return code */ + tRowcnt nEst; /* Number of rows for a single term */ + tRowcnt nRowEst = 0; /* New estimate of the number of rows */ + int i; /* Loop counter */ assert( p->aSample!=0 ); for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){ - nEst = p->aiRowEst[0]; - rc = whereEqualScanEst(pParse, p, pList->a[i].pExpr, &nEst); + nEst = nRow0; + rc = whereEqualScanEst(pParse, pBuilder, pList->a[i].pExpr, &nEst); nRowEst += nEst; + pBuilder->nRecValid = nRecValid; } + if( rc==SQLITE_OK ){ - if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0]; + if( nRowEst > nRow0 ) nRowEst = nRow0; *pnRow = nRowEst; - WHERETRACE(("IN row estimate: est=%g\n", nRowEst)); + WHERETRACE(0x10,("IN row estimate: est=%g\n", nRowEst)); } + assert( pBuilder->nRecValid==nRecValid ); return rc; } -#endif /* defined(SQLITE_ENABLE_STAT3) */ - -/* -** Check to see if column iCol of the table with cursor iTab will appear -** in sorted order according to the current query plan. -** -** Return values: -** -** 0 iCol is not ordered -** 1 iCol has only a single value -** 2 iCol is in ASC order -** 3 iCol is in DESC order -*/ -static int isOrderedColumn( - WhereBestIdx *p, - int iTab, - int iCol -){ - int i, j; - WhereLevel *pLevel = &p->aLevel[p->i-1]; - Index *pIdx; - u8 sortOrder; - for(i=p->i-1; i>=0; i--, pLevel--){ - if( pLevel->iTabCur!=iTab ) continue; - if( (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){ - return 1; - } - assert( (pLevel->plan.wsFlags & WHERE_ORDERED)!=0 ); - if( (pIdx = pLevel->plan.u.pIdx)!=0 ){ - if( iCol<0 ){ - sortOrder = 0; - testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ); - }else{ - int n = pIdx->nColumn; - for(j=0; j<n; j++){ - if( iCol==pIdx->aiColumn[j] ) break; - } - if( j>=n ) return 0; - sortOrder = pIdx->aSortOrder[j]; - testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ); - } - }else{ - if( iCol!=(-1) ) return 0; - sortOrder = 0; - testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ); - } - if( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ){ - assert( sortOrder==0 || sortOrder==1 ); - testcase( sortOrder==1 ); - sortOrder = 1 - sortOrder; - } - return sortOrder+2; - } - return 0; -} - -/* -** This routine decides if pIdx can be used to satisfy the ORDER BY -** clause, either in whole or in part. The return value is the -** cumulative number of terms in the ORDER BY clause that are satisfied -** by the index pIdx and other indices in outer loops. -** -** The table being queried has a cursor number of "base". pIdx is the -** index that is postulated for use to access the table. -** -** The *pbRev value is set to 0 order 1 depending on whether or not -** pIdx should be run in the forward order or in reverse order. -*/ -static int isSortingIndex( - WhereBestIdx *p, /* Best index search context */ - Index *pIdx, /* The index we are testing */ - int base, /* Cursor number for the table to be sorted */ - int *pbRev, /* Set to 1 for reverse-order scan of pIdx */ - int *pbObUnique /* ORDER BY column values will different in every row */ -){ - int i; /* Number of pIdx terms used */ - int j; /* Number of ORDER BY terms satisfied */ - int sortOrder = 2; /* 0: forward. 1: backward. 2: unknown */ - int nTerm; /* Number of ORDER BY terms */ - struct ExprList_item *pOBItem;/* A term of the ORDER BY clause */ - Table *pTab = pIdx->pTable; /* Table that owns index pIdx */ - ExprList *pOrderBy; /* The ORDER BY clause */ - Parse *pParse = p->pParse; /* Parser context */ - sqlite3 *db = pParse->db; /* Database connection */ - int nPriorSat; /* ORDER BY terms satisfied by outer loops */ - int seenRowid = 0; /* True if an ORDER BY rowid term is seen */ - int uniqueNotNull; /* pIdx is UNIQUE with all terms are NOT NULL */ - int outerObUnique; /* Outer loops generate different values in - ** every row for the ORDER BY columns */ - - if( p->i==0 ){ - nPriorSat = 0; - outerObUnique = 1; - }else{ - u32 wsFlags = p->aLevel[p->i-1].plan.wsFlags; - nPriorSat = p->aLevel[p->i-1].plan.nOBSat; - if( (wsFlags & WHERE_ORDERED)==0 ){ - /* This loop cannot be ordered unless the next outer loop is - ** also ordered */ - return nPriorSat; - } - if( OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ){ - /* Only look at the outer-most loop if the OrderByIdxJoin - ** optimization is disabled */ - return nPriorSat; - } - testcase( wsFlags & WHERE_OB_UNIQUE ); - testcase( wsFlags & WHERE_ALL_UNIQUE ); - outerObUnique = (wsFlags & (WHERE_OB_UNIQUE|WHERE_ALL_UNIQUE))!=0; - } - pOrderBy = p->pOrderBy; - assert( pOrderBy!=0 ); - if( pIdx->bUnordered ){ - /* Hash indices (indicated by the "unordered" tag on sqlite_stat1) cannot - ** be used for sorting */ - return nPriorSat; - } - nTerm = pOrderBy->nExpr; - uniqueNotNull = pIdx->onError!=OE_None; - assert( nTerm>0 ); - - /* Argument pIdx must either point to a 'real' named index structure, - ** or an index structure allocated on the stack by bestBtreeIndex() to - ** represent the rowid index that is part of every table. */ - assert( pIdx->zName || (pIdx->nColumn==1 && pIdx->aiColumn[0]==-1) ); - - /* Match terms of the ORDER BY clause against columns of - ** the index. - ** - ** Note that indices have pIdx->nColumn regular columns plus - ** one additional column containing the rowid. The rowid column - ** of the index is also allowed to match against the ORDER BY - ** clause. - */ - j = nPriorSat; - for(i=0,pOBItem=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){ - Expr *pOBExpr; /* The expression of the ORDER BY pOBItem */ - CollSeq *pColl; /* The collating sequence of pOBExpr */ - int termSortOrder; /* Sort order for this term */ - int iColumn; /* The i-th column of the index. -1 for rowid */ - int iSortOrder; /* 1 for DESC, 0 for ASC on the i-th index term */ - int isEq; /* Subject to an == or IS NULL constraint */ - int isMatch; /* ORDER BY term matches the index term */ - const char *zColl; /* Name of collating sequence for i-th index term */ - WhereTerm *pConstraint; /* A constraint in the WHERE clause */ - - /* If the next term of the ORDER BY clause refers to anything other than - ** a column in the "base" table, then this index will not be of any - ** further use in handling the ORDER BY. */ - pOBExpr = sqlite3ExprSkipCollate(pOBItem->pExpr); - if( pOBExpr->op!=TK_COLUMN || pOBExpr->iTable!=base ){ - break; - } - - /* Find column number and collating sequence for the next entry - ** in the index */ - if( pIdx->zName && i<pIdx->nColumn ){ - iColumn = pIdx->aiColumn[i]; - if( iColumn==pIdx->pTable->iPKey ){ - iColumn = -1; - } - iSortOrder = pIdx->aSortOrder[i]; - zColl = pIdx->azColl[i]; - assert( zColl!=0 ); - }else{ - iColumn = -1; - iSortOrder = 0; - zColl = 0; - } - - /* Check to see if the column number and collating sequence of the - ** index match the column number and collating sequence of the ORDER BY - ** clause entry. Set isMatch to 1 if they both match. */ - if( pOBExpr->iColumn==iColumn ){ - if( zColl ){ - pColl = sqlite3ExprCollSeq(pParse, pOBItem->pExpr); - if( !pColl ) pColl = db->pDfltColl; - isMatch = sqlite3StrICmp(pColl->zName, zColl)==0; - }else{ - isMatch = 1; - } - }else{ - isMatch = 0; - } - - /* termSortOrder is 0 or 1 for whether or not the access loop should - ** run forward or backwards (respectively) in order to satisfy this - ** term of the ORDER BY clause. */ - assert( pOBItem->sortOrder==0 || pOBItem->sortOrder==1 ); - assert( iSortOrder==0 || iSortOrder==1 ); - termSortOrder = iSortOrder ^ pOBItem->sortOrder; - - /* If X is the column in the index and ORDER BY clause, check to see - ** if there are any X= or X IS NULL constraints in the WHERE clause. */ - pConstraint = findTerm(p->pWC, base, iColumn, p->notReady, - WO_EQ|WO_ISNULL|WO_IN, pIdx); - if( pConstraint==0 ){ - isEq = 0; - }else if( (pConstraint->eOperator & WO_IN)!=0 ){ - isEq = 0; - }else if( (pConstraint->eOperator & WO_ISNULL)!=0 ){ - uniqueNotNull = 0; - isEq = 1; /* "X IS NULL" means X has only a single value */ - }else if( pConstraint->prereqRight==0 ){ - isEq = 1; /* Constraint "X=constant" means X has only a single value */ - }else{ - Expr *pRight = pConstraint->pExpr->pRight; - if( pRight->op==TK_COLUMN ){ - WHERETRACE((" .. isOrderedColumn(tab=%d,col=%d)", - pRight->iTable, pRight->iColumn)); - isEq = isOrderedColumn(p, pRight->iTable, pRight->iColumn); - WHERETRACE((" -> isEq=%d\n", isEq)); - - /* If the constraint is of the form X=Y where Y is an ordered value - ** in an outer loop, then make sure the sort order of Y matches the - ** sort order required for X. */ - if( isMatch && isEq>=2 && isEq!=pOBItem->sortOrder+2 ){ - testcase( isEq==2 ); - testcase( isEq==3 ); - break; - } - }else{ - isEq = 0; /* "X=expr" places no ordering constraints on X */ - } - } - if( !isMatch ){ - if( isEq==0 ){ - break; - }else{ - continue; - } - }else if( isEq!=1 ){ - if( sortOrder==2 ){ - sortOrder = termSortOrder; - }else if( termSortOrder!=sortOrder ){ - break; - } - } - j++; - pOBItem++; - if( iColumn<0 ){ - seenRowid = 1; - break; - }else if( pTab->aCol[iColumn].notNull==0 && isEq!=1 ){ - testcase( isEq==0 ); - testcase( isEq==2 ); - testcase( isEq==3 ); - uniqueNotNull = 0; - } - } - if( seenRowid ){ - uniqueNotNull = 1; - }else if( uniqueNotNull==0 || i<pIdx->nColumn ){ - uniqueNotNull = 0; - } - - /* If we have not found at least one ORDER BY term that matches the - ** index, then show no progress. */ - if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat; - - /* Either the outer queries must generate rows where there are no two - ** rows with the same values in all ORDER BY columns, or else this - ** loop must generate just a single row of output. Example: Suppose - ** the outer loops generate A=1 and A=1, and this loop generates B=3 - ** and B=4. Then without the following test, ORDER BY A,B would - ** generate the wrong order output: 1,3 1,4 1,3 1,4 - */ - if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat; - *pbObUnique = uniqueNotNull; - - /* Return the necessary scan order back to the caller */ - *pbRev = sortOrder & 1; - - /* If there was an "ORDER BY rowid" term that matched, or it is only - ** possible for a single row from this table to match, then skip over - ** any additional ORDER BY terms dealing with this table. - */ - if( uniqueNotNull ){ - /* Advance j over additional ORDER BY terms associated with base */ - WhereMaskSet *pMS = p->pWC->pMaskSet; - Bitmask m = ~getMask(pMS, base); - while( j<nTerm && (exprTableUsage(pMS, pOrderBy->a[j].pExpr)&m)==0 ){ - j++; - } - } - return j; -} - -/* -** Find the best query plan for accessing a particular table. Write the -** best query plan and its cost into the p->cost. -** -** The lowest cost plan wins. The cost is an estimate of the amount of -** CPU and disk I/O needed to process the requested result. -** Factors that influence cost include: -** -** * The estimated number of rows that will be retrieved. (The -** fewer the better.) -** -** * Whether or not sorting must occur. -** -** * Whether or not there must be separate lookups in the -** index and in the main table. -** -** If there was an INDEXED BY clause (pSrc->pIndex) attached to the table in -** the SQL statement, then this function only considers plans using the -** named index. If no such plan is found, then the returned cost is -** SQLITE_BIG_DBL. If a plan is found that uses the named index, -** then the cost is calculated in the usual way. -** -** If a NOT INDEXED clause was attached to the table -** in the SELECT statement, then no indexes are considered. However, the -** selected plan may still take advantage of the built-in rowid primary key -** index. -*/ -static void bestBtreeIndex(WhereBestIdx *p){ - Parse *pParse = p->pParse; /* The parsing context */ - WhereClause *pWC = p->pWC; /* The WHERE clause */ - struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */ - int iCur = pSrc->iCursor; /* The cursor of the table to be accessed */ - Index *pProbe; /* An index we are evaluating */ - Index *pIdx; /* Copy of pProbe, or zero for IPK index */ - int eqTermMask; /* Current mask of valid equality operators */ - int idxEqTermMask; /* Index mask of valid equality operators */ - Index sPk; /* A fake index object for the primary key */ - tRowcnt aiRowEstPk[2]; /* The aiRowEst[] value for the sPk index */ - int aiColumnPk = -1; /* The aColumn[] value for the sPk index */ - int wsFlagMask; /* Allowed flags in p->cost.plan.wsFlag */ - int nPriorSat; /* ORDER BY terms satisfied by outer loops */ - int nOrderBy; /* Number of ORDER BY terms */ - char bSortInit; /* Initializer for bSort in inner loop */ - char bDistInit; /* Initializer for bDist in inner loop */ - - - /* Initialize the cost to a worst-case value */ - memset(&p->cost, 0, sizeof(p->cost)); - p->cost.rCost = SQLITE_BIG_DBL; - - /* If the pSrc table is the right table of a LEFT JOIN then we may not - ** use an index to satisfy IS NULL constraints on that table. This is - ** because columns might end up being NULL if the table does not match - - ** a circumstance which the index cannot help us discover. Ticket #2177. - */ - if( pSrc->jointype & JT_LEFT ){ - idxEqTermMask = WO_EQ|WO_IN; - }else{ - idxEqTermMask = WO_EQ|WO_IN|WO_ISNULL; - } - - if( pSrc->pIndex ){ - /* An INDEXED BY clause specifies a particular index to use */ - pIdx = pProbe = pSrc->pIndex; - wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE); - eqTermMask = idxEqTermMask; - }else{ - /* There is no INDEXED BY clause. Create a fake Index object in local - ** variable sPk to represent the rowid primary key index. Make this - ** fake index the first in a chain of Index objects with all of the real - ** indices to follow */ - Index *pFirst; /* First of real indices on the table */ - memset(&sPk, 0, sizeof(Index)); - sPk.nColumn = 1; - sPk.aiColumn = &aiColumnPk; - sPk.aiRowEst = aiRowEstPk; - sPk.onError = OE_Replace; - sPk.pTable = pSrc->pTab; - aiRowEstPk[0] = pSrc->pTab->nRowEst; - aiRowEstPk[1] = 1; - pFirst = pSrc->pTab->pIndex; - if( pSrc->notIndexed==0 ){ - /* The real indices of the table are only considered if the - ** NOT INDEXED qualifier is omitted from the FROM clause */ - sPk.pNext = pFirst; - } - pProbe = &sPk; - wsFlagMask = ~( - WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE - ); - eqTermMask = WO_EQ|WO_IN; - pIdx = 0; - } - - nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0; - if( p->i ){ - nPriorSat = p->aLevel[p->i-1].plan.nOBSat; - bSortInit = nPriorSat<nOrderBy; - bDistInit = 0; - }else{ - nPriorSat = 0; - bSortInit = nOrderBy>0; - bDistInit = p->pDistinct!=0; - } - - /* Loop over all indices looking for the best one to use - */ - for(; pProbe; pIdx=pProbe=pProbe->pNext){ - const tRowcnt * const aiRowEst = pProbe->aiRowEst; - WhereCost pc; /* Cost of using pProbe */ - double log10N = (double)1; /* base-10 logarithm of nRow (inexact) */ - - /* The following variables are populated based on the properties of - ** index being evaluated. They are then used to determine the expected - ** cost and number of rows returned. - ** - ** pc.plan.nEq: - ** Number of equality terms that can be implemented using the index. - ** In other words, the number of initial fields in the index that - ** are used in == or IN or NOT NULL constraints of the WHERE clause. - ** - ** nInMul: - ** The "in-multiplier". This is an estimate of how many seek operations - ** SQLite must perform on the index in question. For example, if the - ** WHERE clause is: - ** - ** WHERE a IN (1, 2, 3) AND b IN (4, 5, 6) - ** - ** SQLite must perform 9 lookups on an index on (a, b), so nInMul is - ** set to 9. Given the same schema and either of the following WHERE - ** clauses: - ** - ** WHERE a = 1 - ** WHERE a >= 2 - ** - ** nInMul is set to 1. - ** - ** If there exists a WHERE term of the form "x IN (SELECT ...)", then - ** the sub-select is assumed to return 25 rows for the purposes of - ** determining nInMul. - ** - ** bInEst: - ** Set to true if there was at least one "x IN (SELECT ...)" term used - ** in determining the value of nInMul. Note that the RHS of the - ** IN operator must be a SELECT, not a value list, for this variable - ** to be true. - ** - ** rangeDiv: - ** An estimate of a divisor by which to reduce the search space due - ** to inequality constraints. In the absence of sqlite_stat3 ANALYZE - ** data, a single inequality reduces the search space to 1/4rd its - ** original size (rangeDiv==4). Two inequalities reduce the search - ** space to 1/16th of its original size (rangeDiv==16). - ** - ** bSort: - ** Boolean. True if there is an ORDER BY clause that will require an - ** external sort (i.e. scanning the index being evaluated will not - ** correctly order records). - ** - ** bDist: - ** Boolean. True if there is a DISTINCT clause that will require an - ** external btree. - ** - ** bLookup: - ** Boolean. True if a table lookup is required for each index entry - ** visited. In other words, true if this is not a covering index. - ** This is always false for the rowid primary key index of a table. - ** For other indexes, it is true unless all the columns of the table - ** used by the SELECT statement are present in the index (such an - ** index is sometimes described as a covering index). - ** For example, given the index on (a, b), the second of the following - ** two queries requires table b-tree lookups in order to find the value - ** of column c, but the first does not because columns a and b are - ** both available in the index. - ** - ** SELECT a, b FROM tbl WHERE a = 1; - ** SELECT a, b, c FROM tbl WHERE a = 1; - */ - int bInEst = 0; /* True if "x IN (SELECT...)" seen */ - int nInMul = 1; /* Number of distinct equalities to lookup */ - double rangeDiv = (double)1; /* Estimated reduction in search space */ - int nBound = 0; /* Number of range constraints seen */ - char bSort = bSortInit; /* True if external sort required */ - char bDist = bDistInit; /* True if index cannot help with DISTINCT */ - char bLookup = 0; /* True if not a covering index */ - WhereTerm *pTerm; /* A single term of the WHERE clause */ -#ifdef SQLITE_ENABLE_STAT3 - WhereTerm *pFirstTerm = 0; /* First term matching the index */ -#endif - - WHERETRACE(( - " %s(%s):\n", - pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk") - )); - memset(&pc, 0, sizeof(pc)); - pc.plan.nOBSat = nPriorSat; - - /* Determine the values of pc.plan.nEq and nInMul */ - for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){ - int j = pProbe->aiColumn[pc.plan.nEq]; - pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx); - if( pTerm==0 ) break; - pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ); - testcase( pTerm->pWC!=pWC ); - if( pTerm->eOperator & WO_IN ){ - Expr *pExpr = pTerm->pExpr; - pc.plan.wsFlags |= WHERE_COLUMN_IN; - if( ExprHasProperty(pExpr, EP_xIsSelect) ){ - /* "x IN (SELECT ...)": Assume the SELECT returns 25 rows */ - nInMul *= 25; - bInEst = 1; - }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){ - /* "x IN (value, value, ...)" */ - nInMul *= pExpr->x.pList->nExpr; - } - }else if( pTerm->eOperator & WO_ISNULL ){ - pc.plan.wsFlags |= WHERE_COLUMN_NULL; - } -#ifdef SQLITE_ENABLE_STAT3 - if( pc.plan.nEq==0 && pProbe->aSample ) pFirstTerm = pTerm; -#endif - pc.used |= pTerm->prereqRight; - } - - /* If the index being considered is UNIQUE, and there is an equality - ** constraint for all columns in the index, then this search will find - ** at most a single row. In this case set the WHERE_UNIQUE flag to - ** indicate this to the caller. - ** - ** Otherwise, if the search may find more than one row, test to see if - ** there is a range constraint on indexed column (pc.plan.nEq+1) that - ** can be optimized using the index. - */ - if( pc.plan.nEq==pProbe->nColumn && pProbe->onError!=OE_None ){ - testcase( pc.plan.wsFlags & WHERE_COLUMN_IN ); - testcase( pc.plan.wsFlags & WHERE_COLUMN_NULL ); - if( (pc.plan.wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){ - pc.plan.wsFlags |= WHERE_UNIQUE; - if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){ - pc.plan.wsFlags |= WHERE_ALL_UNIQUE; - } - } - }else if( pProbe->bUnordered==0 ){ - int j; - j = (pc.plan.nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[pc.plan.nEq]); - if( findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){ - WhereTerm *pTop, *pBtm; - pTop = findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE, pIdx); - pBtm = findTerm(pWC, iCur, j, p->notReady, WO_GT|WO_GE, pIdx); - whereRangeScanEst(pParse, pProbe, pc.plan.nEq, pBtm, pTop, &rangeDiv); - if( pTop ){ - nBound = 1; - pc.plan.wsFlags |= WHERE_TOP_LIMIT; - pc.used |= pTop->prereqRight; - testcase( pTop->pWC!=pWC ); - } - if( pBtm ){ - nBound++; - pc.plan.wsFlags |= WHERE_BTM_LIMIT; - pc.used |= pBtm->prereqRight; - testcase( pBtm->pWC!=pWC ); - } - pc.plan.wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE); - } - } - - /* If there is an ORDER BY clause and the index being considered will - ** naturally scan rows in the required order, set the appropriate flags - ** in pc.plan.wsFlags. Otherwise, if there is an ORDER BY clause but - ** the index will scan rows in a different order, set the bSort - ** variable. */ - if( bSort && (pSrc->jointype & JT_LEFT)==0 ){ - int bRev = 2; - int bObUnique = 0; - WHERETRACE((" --> before isSortIndex: nPriorSat=%d\n",nPriorSat)); - pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev, &bObUnique); - WHERETRACE((" --> after isSortIndex: bRev=%d bObU=%d nOBSat=%d\n", - bRev, bObUnique, pc.plan.nOBSat)); - if( nPriorSat<pc.plan.nOBSat || (pc.plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){ - pc.plan.wsFlags |= WHERE_ORDERED; - if( bObUnique ) pc.plan.wsFlags |= WHERE_OB_UNIQUE; - } - if( nOrderBy==pc.plan.nOBSat ){ - bSort = 0; - pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE; - } - if( bRev & 1 ) pc.plan.wsFlags |= WHERE_REVERSE; - } - - /* If there is a DISTINCT qualifier and this index will scan rows in - ** order of the DISTINCT expressions, clear bDist and set the appropriate - ** flags in pc.plan.wsFlags. */ - if( bDist - && isDistinctIndex(pParse, pWC, pProbe, iCur, p->pDistinct, pc.plan.nEq) - && (pc.plan.wsFlags & WHERE_COLUMN_IN)==0 - ){ - bDist = 0; - pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT; - } - - /* If currently calculating the cost of using an index (not the IPK - ** index), determine if all required column data may be obtained without - ** using the main table (i.e. if the index is a covering - ** index for this query). If it is, set the WHERE_IDX_ONLY flag in - ** pc.plan.wsFlags. Otherwise, set the bLookup variable to true. */ - if( pIdx ){ - Bitmask m = pSrc->colUsed; - int j; - for(j=0; j<pIdx->nColumn; j++){ - int x = pIdx->aiColumn[j]; - if( x<BMS-1 ){ - m &= ~(((Bitmask)1)<<x); - } - } - if( m==0 ){ - pc.plan.wsFlags |= WHERE_IDX_ONLY; - }else{ - bLookup = 1; - } - } - - /* - ** Estimate the number of rows of output. For an "x IN (SELECT...)" - ** constraint, do not let the estimate exceed half the rows in the table. - */ - pc.plan.nRow = (double)(aiRowEst[pc.plan.nEq] * nInMul); - if( bInEst && pc.plan.nRow*2>aiRowEst[0] ){ - pc.plan.nRow = aiRowEst[0]/2; - nInMul = (int)(pc.plan.nRow / aiRowEst[pc.plan.nEq]); - } - -#ifdef SQLITE_ENABLE_STAT3 - /* If the constraint is of the form x=VALUE or x IN (E1,E2,...) - ** and we do not think that values of x are unique and if histogram - ** data is available for column x, then it might be possible - ** to get a better estimate on the number of rows based on - ** VALUE and how common that value is according to the histogram. - */ - if( pc.plan.nRow>(double)1 && pc.plan.nEq==1 - && pFirstTerm!=0 && aiRowEst[1]>1 ){ - assert( (pFirstTerm->eOperator & (WO_EQ|WO_ISNULL|WO_IN))!=0 ); - if( pFirstTerm->eOperator & (WO_EQ|WO_ISNULL) ){ - testcase( pFirstTerm->eOperator & WO_EQ ); - testcase( pFirstTerm->eOperator & WO_EQUIV ); - testcase( pFirstTerm->eOperator & WO_ISNULL ); - whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight, - &pc.plan.nRow); - }else if( bInEst==0 ){ - assert( pFirstTerm->eOperator & WO_IN ); - whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList, - &pc.plan.nRow); - } - } -#endif /* SQLITE_ENABLE_STAT3 */ - - /* Adjust the number of output rows and downward to reflect rows - ** that are excluded by range constraints. - */ - pc.plan.nRow = pc.plan.nRow/rangeDiv; - if( pc.plan.nRow<1 ) pc.plan.nRow = 1; - - /* Experiments run on real SQLite databases show that the time needed - ** to do a binary search to locate a row in a table or index is roughly - ** log10(N) times the time to move from one row to the next row within - ** a table or index. The actual times can vary, with the size of - ** records being an important factor. Both moves and searches are - ** slower with larger records, presumably because fewer records fit - ** on one page and hence more pages have to be fetched. - ** - ** The ANALYZE command and the sqlite_stat1 and sqlite_stat3 tables do - ** not give us data on the relative sizes of table and index records. - ** So this computation assumes table records are about twice as big - ** as index records - */ - if( (pc.plan.wsFlags&~(WHERE_REVERSE|WHERE_ORDERED|WHERE_OB_UNIQUE)) - ==WHERE_IDX_ONLY - && (pWC->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 - && sqlite3GlobalConfig.bUseCis - && OptimizationEnabled(pParse->db, SQLITE_CoverIdxScan) - ){ - /* This index is not useful for indexing, but it is a covering index. - ** A full-scan of the index might be a little faster than a full-scan - ** of the table, so give this case a cost slightly less than a table - ** scan. */ - pc.rCost = aiRowEst[0]*3 + pProbe->nColumn; - pc.plan.wsFlags |= WHERE_COVER_SCAN|WHERE_COLUMN_RANGE; - }else if( (pc.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){ - /* The cost of a full table scan is a number of move operations equal - ** to the number of rows in the table. - ** - ** We add an additional 4x penalty to full table scans. This causes - ** the cost function to err on the side of choosing an index over - ** choosing a full scan. This 4x full-scan penalty is an arguable - ** decision and one which we expect to revisit in the future. But - ** it seems to be working well enough at the moment. - */ - pc.rCost = aiRowEst[0]*4; - pc.plan.wsFlags &= ~WHERE_IDX_ONLY; - if( pIdx ){ - pc.plan.wsFlags &= ~WHERE_ORDERED; - pc.plan.nOBSat = nPriorSat; - } - }else{ - log10N = estLog(aiRowEst[0]); - pc.rCost = pc.plan.nRow; - if( pIdx ){ - if( bLookup ){ - /* For an index lookup followed by a table lookup: - ** nInMul index searches to find the start of each index range - ** + nRow steps through the index - ** + nRow table searches to lookup the table entry using the rowid - */ - pc.rCost += (nInMul + pc.plan.nRow)*log10N; - }else{ - /* For a covering index: - ** nInMul index searches to find the initial entry - ** + nRow steps through the index - */ - pc.rCost += nInMul*log10N; - } - }else{ - /* For a rowid primary key lookup: - ** nInMult table searches to find the initial entry for each range - ** + nRow steps through the table - */ - pc.rCost += nInMul*log10N; - } - } - - /* Add in the estimated cost of sorting the result. Actual experimental - ** measurements of sorting performance in SQLite show that sorting time - ** adds C*N*log10(N) to the cost, where N is the number of rows to be - ** sorted and C is a factor between 1.95 and 4.3. We will split the - ** difference and select C of 3.0. - */ - if( bSort ){ - double m = estLog(pc.plan.nRow*(nOrderBy - pc.plan.nOBSat)/nOrderBy); - m *= (double)(pc.plan.nOBSat ? 2 : 3); - pc.rCost += pc.plan.nRow*m; - } - if( bDist ){ - pc.rCost += pc.plan.nRow*estLog(pc.plan.nRow)*3; - } - - /**** Cost of using this index has now been computed ****/ - - /* If there are additional constraints on this table that cannot - ** be used with the current index, but which might lower the number - ** of output rows, adjust the nRow value accordingly. This only - ** matters if the current index is the least costly, so do not bother - ** with this step if we already know this index will not be chosen. - ** Also, never reduce the output row count below 2 using this step. - ** - ** It is critical that the notValid mask be used here instead of - ** the notReady mask. When computing an "optimal" index, the notReady - ** mask will only have one bit set - the bit for the current table. - ** The notValid mask, on the other hand, always has all bits set for - ** tables that are not in outer loops. If notReady is used here instead - ** of notValid, then a optimal index that depends on inner joins loops - ** might be selected even when there exists an optimal index that has - ** no such dependency. - */ - if( pc.plan.nRow>2 && pc.rCost<=p->cost.rCost ){ - int k; /* Loop counter */ - int nSkipEq = pc.plan.nEq; /* Number of == constraints to skip */ - int nSkipRange = nBound; /* Number of < constraints to skip */ - Bitmask thisTab; /* Bitmap for pSrc */ - - thisTab = getMask(pWC->pMaskSet, iCur); - for(pTerm=pWC->a, k=pWC->nTerm; pc.plan.nRow>2 && k; k--, pTerm++){ - if( pTerm->wtFlags & TERM_VIRTUAL ) continue; - if( (pTerm->prereqAll & p->notValid)!=thisTab ) continue; - if( pTerm->eOperator & (WO_EQ|WO_IN|WO_ISNULL) ){ - if( nSkipEq ){ - /* Ignore the first pc.plan.nEq equality matches since the index - ** has already accounted for these */ - nSkipEq--; - }else{ - /* Assume each additional equality match reduces the result - ** set size by a factor of 10 */ - pc.plan.nRow /= 10; - } - }else if( pTerm->eOperator & (WO_LT|WO_LE|WO_GT|WO_GE) ){ - if( nSkipRange ){ - /* Ignore the first nSkipRange range constraints since the index - ** has already accounted for these */ - nSkipRange--; - }else{ - /* Assume each additional range constraint reduces the result - ** set size by a factor of 3. Indexed range constraints reduce - ** the search space by a larger factor: 4. We make indexed range - ** more selective intentionally because of the subjective - ** observation that indexed range constraints really are more - ** selective in practice, on average. */ - pc.plan.nRow /= 3; - } - }else if( (pTerm->eOperator & WO_NOOP)==0 ){ - /* Any other expression lowers the output row count by half */ - pc.plan.nRow /= 2; - } - } - if( pc.plan.nRow<2 ) pc.plan.nRow = 2; - } - - - WHERETRACE(( - " nEq=%d nInMul=%d rangeDiv=%d bSort=%d bLookup=%d wsFlags=0x%08x\n" - " notReady=0x%llx log10N=%.1f nRow=%.1f cost=%.1f\n" - " used=0x%llx nOBSat=%d\n", - pc.plan.nEq, nInMul, (int)rangeDiv, bSort, bLookup, pc.plan.wsFlags, - p->notReady, log10N, pc.plan.nRow, pc.rCost, pc.used, - pc.plan.nOBSat - )); - - /* If this index is the best we have seen so far, then record this - ** index and its cost in the p->cost structure. - */ - if( (!pIdx || pc.plan.wsFlags) && compareCost(&pc, &p->cost) ){ - p->cost = pc; - p->cost.plan.wsFlags &= wsFlagMask; - p->cost.plan.u.pIdx = pIdx; - } - - /* If there was an INDEXED BY clause, then only that one index is - ** considered. */ - if( pSrc->pIndex ) break; - - /* Reset masks for the next index in the loop */ - wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE); - eqTermMask = idxEqTermMask; - } - - /* If there is no ORDER BY clause and the SQLITE_ReverseOrder flag - ** is set, then reverse the order that the index will be scanned - ** in. This is used for application testing, to help find cases - ** where application behavior depends on the (undefined) order that - ** SQLite outputs rows in in the absence of an ORDER BY clause. */ - if( !p->pOrderBy && pParse->db->flags & SQLITE_ReverseOrder ){ - p->cost.plan.wsFlags |= WHERE_REVERSE; - } - - assert( p->pOrderBy || (p->cost.plan.wsFlags&WHERE_ORDERED)==0 ); - assert( p->cost.plan.u.pIdx==0 || (p->cost.plan.wsFlags&WHERE_ROWID_EQ)==0 ); - assert( pSrc->pIndex==0 - || p->cost.plan.u.pIdx==0 - || p->cost.plan.u.pIdx==pSrc->pIndex - ); - - WHERETRACE((" best index is %s cost=%.1f\n", - p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk", - p->cost.rCost)); - - bestOrClauseIndex(p); - bestAutomaticIndex(p); - p->cost.plan.wsFlags |= eqTermMask; -} - -/* -** Find the query plan for accessing table pSrc->pTab. Write the -** best query plan and its cost into the WhereCost object supplied -** as the last parameter. This function may calculate the cost of -** both real and virtual table scans. -** -** This function does not take ORDER BY or DISTINCT into account. Nor -** does it remember the virtual table query plan. All it does is compute -** the cost while determining if an OR optimization is applicable. The -** details will be reconsidered later if the optimization is found to be -** applicable. -*/ -static void bestIndex(WhereBestIdx *p){ -#ifndef SQLITE_OMIT_VIRTUALTABLE - if( IsVirtual(p->pSrc->pTab) ){ - sqlite3_index_info *pIdxInfo = 0; - p->ppIdxInfo = &pIdxInfo; - bestVirtualIndex(p); - assert( pIdxInfo!=0 || p->pParse->db->mallocFailed ); - if( pIdxInfo && pIdxInfo->needToFreeIdxStr ){ - sqlite3_free(pIdxInfo->idxStr); - } - sqlite3DbFree(p->pParse->db, pIdxInfo); - }else -#endif - { - bestBtreeIndex(p); - } -} +#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ /* ** Disable a term in the WHERE clause. Except, do not disable the term @@ -3731,9 +2412,6 @@ static void bestIndex(WhereBestIdx *p){ ** in the ON clause. The term is disabled in (3) because it is not part ** of a LEFT OUTER JOIN. In (1), the term is not disabled. ** -** IMPLEMENTATION-OF: R-24597-58655 No tests are done for terms that are -** completely satisfied by indices. -** ** Disabling a term causes that term to not be tested in the inner loop ** of the join. Disabling is an optimization. When terms are satisfied ** by indices, we disable them to prevent redundant tests in the inner @@ -3746,6 +2424,7 @@ static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){ if( pTerm && (pTerm->wtFlags & TERM_CODED)==0 && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin)) + && (pLevel->notReady & pTerm->prereqAll)==0 ){ pTerm->wtFlags |= TERM_CODED; if( pTerm->iParent>=0 ){ @@ -3813,6 +2492,7 @@ static int codeEqualityTerm( WhereTerm *pTerm, /* The term of the WHERE clause to be coded */ WhereLevel *pLevel, /* The level of the FROM clause we are working on */ int iEq, /* Index of the equality term within this level */ + int bRev, /* True for reverse-order IN operations */ int iTarget /* Attempt to leave results in this register */ ){ Expr *pX = pTerm->pExpr; @@ -3830,27 +2510,29 @@ static int codeEqualityTerm( int eType; int iTab; struct InLoop *pIn; - u8 bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0; + WhereLoop *pLoop = pLevel->pWLoop; - if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 - && pLevel->plan.u.pIdx->aSortOrder[iEq] + if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 + && pLoop->u.btree.pIndex!=0 + && pLoop->u.btree.pIndex->aSortOrder[iEq] ){ testcase( iEq==0 ); - testcase( iEq==pLevel->plan.u.pIdx->nColumn-1 ); - testcase( iEq>0 && iEq+1<pLevel->plan.u.pIdx->nColumn ); testcase( bRev ); bRev = !bRev; } assert( pX->op==TK_IN ); iReg = iTarget; - eType = sqlite3FindInIndex(pParse, pX, 0); + eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0); if( eType==IN_INDEX_INDEX_DESC ){ testcase( bRev ); bRev = !bRev; } iTab = pX->iTable; sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0); - assert( pLevel->plan.wsFlags & WHERE_IN_ABLE ); + VdbeCoverageIf(v, bRev); + VdbeCoverageIf(v, !bRev); + assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 ); + pLoop->wsFlags |= WHERE_IN_ABLE; if( pLevel->u.in.nIn==0 ){ pLevel->addrNxt = sqlite3VdbeMakeLabel(v); } @@ -3867,8 +2549,8 @@ static int codeEqualityTerm( }else{ pIn->addrInTop = sqlite3VdbeAddOp3(v, OP_Column, iTab, 0, iReg); } - pIn->eEndLoopOp = bRev ? OP_Prev : OP_Next; - sqlite3VdbeAddOp1(v, OP_IsNull, iReg); + pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen; + sqlite3VdbeAddOp1(v, OP_IsNull, iReg); VdbeCoverage(v); }else{ pLevel->u.in.nIn = 0; } @@ -3880,7 +2562,7 @@ static int codeEqualityTerm( /* ** Generate code that will evaluate all == and IN constraints for an -** index. +** index scan. ** ** For example, consider table t1(a,b,c,d,e,f) with index i1(a,b,c). ** Suppose the WHERE clause is this: a==5 AND b IN (1,2,3) AND c>5 AND c<10 @@ -3895,9 +2577,15 @@ static int codeEqualityTerm( ** The only thing it does is allocate the pLevel->iMem memory cell and ** compute the affinity string. ** -** This routine always allocates at least one memory cell and returns -** the index of that memory cell. The code that -** calls this routine will use that memory cell to store the termination +** The nExtraReg parameter is 0 or 1. It is 0 if all WHERE clause constraints +** are == or IN and are covered by the nEq. nExtraReg is 1 if there is +** an inequality constraint (such as the "c>=5 AND c<10" in the example) that +** occurs after the nEq quality constraints. +** +** This routine allocates a range of nEq+nExtraReg memory cells and returns +** the index of the first memory cell in that range. The code that +** calls this routine will use that memory range to store keys for +** start and termination conditions of the loop. ** key value of the loop. If one or more IN operators appear, then ** this routine allocates an additional nEq memory cells for internal ** use. @@ -3920,29 +2608,33 @@ static int codeEqualityTerm( static int codeAllEqualityTerms( Parse *pParse, /* Parsing context */ WhereLevel *pLevel, /* Which nested loop of the FROM we are coding */ - WhereClause *pWC, /* The WHERE clause */ - Bitmask notReady, /* Which parts of FROM have not yet been coded */ + int bRev, /* Reverse the order of IN operators */ int nExtraReg, /* Number of extra registers to allocate */ char **pzAff /* OUT: Set to point to affinity string */ ){ - int nEq = pLevel->plan.nEq; /* The number of == or IN constraints to code */ + u16 nEq; /* The number of == or IN constraints to code */ + u16 nSkip; /* Number of left-most columns to skip */ Vdbe *v = pParse->pVdbe; /* The vm under construction */ Index *pIdx; /* The index being used for this loop */ - int iCur = pLevel->iTabCur; /* The cursor of the table */ WhereTerm *pTerm; /* A single constraint term */ + WhereLoop *pLoop; /* The WhereLoop object */ int j; /* Loop counter */ int regBase; /* Base register */ int nReg; /* Number of registers to allocate */ char *zAff; /* Affinity string to return */ /* This module is only called on query plans that use an index. */ - assert( pLevel->plan.wsFlags & WHERE_INDEXED ); - pIdx = pLevel->plan.u.pIdx; + pLoop = pLevel->pWLoop; + assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ); + nEq = pLoop->u.btree.nEq; + nSkip = pLoop->u.btree.nSkip; + pIdx = pLoop->u.btree.pIndex; + assert( pIdx!=0 ); /* Figure out how many memory cells we will need then allocate them. */ regBase = pParse->nMem + 1; - nReg = pLevel->plan.nEq + nExtraReg; + nReg = pLoop->u.btree.nEq + nExtraReg; pParse->nMem += nReg; zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx)); @@ -3950,19 +2642,37 @@ static int codeAllEqualityTerms( pParse->db->mallocFailed = 1; } + if( nSkip ){ + int iIdxCur = pLevel->iIdxCur; + sqlite3VdbeAddOp1(v, (bRev?OP_Last:OP_Rewind), iIdxCur); + VdbeCoverageIf(v, bRev==0); + VdbeCoverageIf(v, bRev!=0); + VdbeComment((v, "begin skip-scan on %s", pIdx->zName)); + j = sqlite3VdbeAddOp0(v, OP_Goto); + pLevel->addrSkip = sqlite3VdbeAddOp4Int(v, (bRev?OP_SeekLT:OP_SeekGT), + iIdxCur, 0, regBase, nSkip); + VdbeCoverageIf(v, bRev==0); + VdbeCoverageIf(v, bRev!=0); + sqlite3VdbeJumpHere(v, j); + for(j=0; j<nSkip; j++){ + sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, j, regBase+j); + assert( pIdx->aiColumn[j]>=0 ); + VdbeComment((v, "%s", pIdx->pTable->aCol[pIdx->aiColumn[j]].zName)); + } + } + /* Evaluate the equality constraints */ - assert( pIdx->nColumn>=nEq ); - for(j=0; j<nEq; j++){ + assert( zAff==0 || (int)strlen(zAff)>=nEq ); + for(j=nSkip; j<nEq; j++){ int r1; - int k = pIdx->aiColumn[j]; - pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx); - if( pTerm==0 ) break; - /* The following true for indices with redundant columns. + pTerm = pLoop->aLTerm[j]; + assert( pTerm!=0 ); + /* The following testcase is true for indices with redundant columns. ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */ testcase( (pTerm->wtFlags & TERM_CODED)!=0 ); - testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ - r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, regBase+j); + testcase( pTerm->wtFlags & TERM_VIRTUAL ); + r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j); if( r1!=regBase+j ){ if( nReg==1 ){ sqlite3ReleaseTempReg(pParse, regBase); @@ -3975,7 +2685,10 @@ static int codeAllEqualityTerms( testcase( pTerm->eOperator & WO_IN ); if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){ Expr *pRight = pTerm->pExpr->pRight; - sqlite3ExprCodeIsNullJump(v, pRight, regBase+j, pLevel->addrBrk); + if( sqlite3ExprCanBeNull(pRight) ){ + sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk); + VdbeCoverage(v); + } if( zAff ){ if( sqlite3CompareAffinity(pRight, zAff[j])==SQLITE_AFF_NONE ){ zAff[j] = SQLITE_AFF_NONE; @@ -4006,7 +2719,7 @@ static void explainAppendTerm( const char *zOp /* Name of the operator */ ){ if( iTerm ) sqlite3StrAccumAppend(pStr, " AND ", 5); - sqlite3StrAccumAppend(pStr, zColumn, -1); + sqlite3StrAccumAppendAll(pStr, zColumn); sqlite3StrAccumAppend(pStr, zOp, 1); sqlite3StrAccumAppend(pStr, "?", 1); } @@ -4030,32 +2743,40 @@ static void explainAppendTerm( ** It is the responsibility of the caller to free the buffer when it is ** no longer required. */ -static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){ - WherePlan *pPlan = &pLevel->plan; - Index *pIndex = pPlan->u.pIdx; - int nEq = pPlan->nEq; +static char *explainIndexRange(sqlite3 *db, WhereLoop *pLoop, Table *pTab){ + Index *pIndex = pLoop->u.btree.pIndex; + u16 nEq = pLoop->u.btree.nEq; + u16 nSkip = pLoop->u.btree.nSkip; int i, j; Column *aCol = pTab->aCol; - int *aiColumn = pIndex->aiColumn; + i16 *aiColumn = pIndex->aiColumn; StrAccum txt; - if( nEq==0 && (pPlan->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){ + if( nEq==0 && (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){ return 0; } sqlite3StrAccumInit(&txt, 0, 0, SQLITE_MAX_LENGTH); txt.db = db; sqlite3StrAccumAppend(&txt, " (", 2); for(i=0; i<nEq; i++){ - explainAppendTerm(&txt, i, aCol[aiColumn[i]].zName, "="); + char *z = aiColumn[i] < 0 ? "rowid" : aCol[aiColumn[i]].zName; + if( i>=nSkip ){ + explainAppendTerm(&txt, i, z, "="); + }else{ + if( i ) sqlite3StrAccumAppend(&txt, " AND ", 5); + sqlite3StrAccumAppend(&txt, "ANY(", 4); + sqlite3StrAccumAppendAll(&txt, z); + sqlite3StrAccumAppend(&txt, ")", 1); + } } j = i; - if( pPlan->wsFlags&WHERE_BTM_LIMIT ){ - char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName; + if( pLoop->wsFlags&WHERE_BTM_LIMIT ){ + char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName; explainAppendTerm(&txt, i++, z, ">"); } - if( pPlan->wsFlags&WHERE_TOP_LIMIT ){ - char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName; + if( pLoop->wsFlags&WHERE_TOP_LIMIT ){ + char *z = aiColumn[j] < 0 ? "rowid" : aCol[aiColumn[j]].zName; explainAppendTerm(&txt, i, z, "<"); } sqlite3StrAccumAppend(&txt, ")", 1); @@ -4076,21 +2797,26 @@ static void explainOneScan( int iFrom, /* Value for "from" column of output */ u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */ ){ - if( pParse->explain==2 ){ - u32 flags = pLevel->plan.wsFlags; +#ifndef SQLITE_DEBUG + if( pParse->explain==2 ) +#endif + { struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom]; Vdbe *v = pParse->pVdbe; /* VM being constructed */ sqlite3 *db = pParse->db; /* Database handle */ char *zMsg; /* Text to add to EQP output */ - sqlite3_int64 nRow; /* Expected number of rows visited by scan */ int iId = pParse->iSelectId; /* Select id (left-most output column) */ int isSearch; /* True for a SEARCH. False for SCAN. */ + WhereLoop *pLoop; /* The controlling WhereLoop object */ + u32 flags; /* Flags that describe this loop */ + pLoop = pLevel->pWLoop; + flags = pLoop->wsFlags; if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return; - isSearch = (pLevel->plan.nEq>0) - || (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 - || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX)); + isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 + || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0)) + || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX)); zMsg = sqlite3MPrintf(db, "%s", isSearch?"SEARCH":"SCAN"); if( pItem->pSelect ){ @@ -4102,43 +2828,44 @@ static void explainOneScan( if( pItem->zAlias ){ zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias); } - if( (flags & WHERE_INDEXED)!=0 ){ - char *zWhere = explainIndexRange(db, pLevel, pItem->pTab); - zMsg = sqlite3MAppendf(db, zMsg, "%s USING %s%sINDEX%s%s%s", zMsg, - ((flags & WHERE_TEMP_INDEX)?"AUTOMATIC ":""), - ((flags & WHERE_IDX_ONLY)?"COVERING ":""), - ((flags & WHERE_TEMP_INDEX)?"":" "), - ((flags & WHERE_TEMP_INDEX)?"": pLevel->plan.u.pIdx->zName), - zWhere - ); + if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0 + && ALWAYS(pLoop->u.btree.pIndex!=0) + ){ + const char *zFmt; + Index *pIdx = pLoop->u.btree.pIndex; + char *zWhere = explainIndexRange(db, pLoop, pItem->pTab); + assert( !(flags&WHERE_AUTO_INDEX) || (flags&WHERE_IDX_ONLY) ); + if( !HasRowid(pItem->pTab) && IsPrimaryKeyIndex(pIdx) ){ + zFmt = zWhere ? "%s USING PRIMARY KEY%.0s%s" : "%s%.0s%s"; + }else if( flags & WHERE_AUTO_INDEX ){ + zFmt = "%s USING AUTOMATIC COVERING INDEX%.0s%s"; + }else if( flags & WHERE_IDX_ONLY ){ + zFmt = "%s USING COVERING INDEX %s%s"; + }else{ + zFmt = "%s USING INDEX %s%s"; + } + zMsg = sqlite3MAppendf(db, zMsg, zFmt, zMsg, pIdx->zName, zWhere); sqlite3DbFree(db, zWhere); - }else if( flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){ + }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){ zMsg = sqlite3MAppendf(db, zMsg, "%s USING INTEGER PRIMARY KEY", zMsg); - if( flags&WHERE_ROWID_EQ ){ + if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){ zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid=?)", zMsg); }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){ zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>? AND rowid<?)", zMsg); }else if( flags&WHERE_BTM_LIMIT ){ zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>?)", zMsg); - }else if( flags&WHERE_TOP_LIMIT ){ + }else if( ALWAYS(flags&WHERE_TOP_LIMIT) ){ zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid<?)", zMsg); } } #ifndef SQLITE_OMIT_VIRTUALTABLE else if( (flags & WHERE_VIRTUALTABLE)!=0 ){ - sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx; zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg, - pVtabIdx->idxNum, pVtabIdx->idxStr); + pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr); } #endif - if( wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) ){ - testcase( wctrlFlags & WHERE_ORDERBY_MIN ); - nRow = 1; - }else{ - nRow = (sqlite3_int64)pLevel->plan.nRow; - } - zMsg = sqlite3MAppendf(db, zMsg, "%s (~%lld rows)", zMsg, nRow); + zMsg = sqlite3MAppendf(db, zMsg, "%s", zMsg); sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC); } } @@ -4154,7 +2881,6 @@ static void explainOneScan( static Bitmask codeOneLoopStart( WhereInfo *pWInfo, /* Complete information about the WHERE clause */ int iLevel, /* Which level of pWInfo->a[] should be coded */ - u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */ Bitmask notReady /* Which tables are currently available */ ){ int j, k; /* Loop counters */ @@ -4163,27 +2889,31 @@ static Bitmask codeOneLoopStart( int omitTable; /* True if we use the index only */ int bRev; /* True if we need to scan in reverse order */ WhereLevel *pLevel; /* The where level to be coded */ + WhereLoop *pLoop; /* The WhereLoop object being coded */ WhereClause *pWC; /* Decomposition of the entire WHERE clause */ WhereTerm *pTerm; /* A WHERE clause term */ Parse *pParse; /* Parsing context */ + sqlite3 *db; /* Database connection */ Vdbe *v; /* The prepared stmt under constructions */ struct SrcList_item *pTabItem; /* FROM clause term being coded */ int addrBrk; /* Jump here to break out of the loop */ int addrCont; /* Jump here to continue with next cycle */ int iRowidReg = 0; /* Rowid is stored in this register, if not zero */ int iReleaseReg = 0; /* Temp register to free before returning */ - Bitmask newNotReady; /* Return value */ pParse = pWInfo->pParse; v = pParse->pVdbe; - pWC = pWInfo->pWC; + pWC = &pWInfo->sWC; + db = pParse->db; pLevel = &pWInfo->a[iLevel]; + pLoop = pLevel->pWLoop; pTabItem = &pWInfo->pTabList->a[pLevel->iFrom]; iCur = pTabItem->iCursor; - bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0; - omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0 - && (wctrlFlags & WHERE_FORCE_TABLE)==0; - VdbeNoopComment((v, "Begin Join Loop %d", iLevel)); + pLevel->notReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur); + bRev = (pWInfo->revMask>>iLevel)&1; + omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 + && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0; + VdbeModuleComment((v, "Begin WHERE-loop%d: %s",iLevel,pTabItem->pTab->zName)); /* Create labels for the "break" and "continue" instructions ** for the current loop. Jump to addrBrk to break out of a loop. @@ -4211,87 +2941,85 @@ static Bitmask codeOneLoopStart( /* Special case of a FROM clause subquery implemented as a co-routine */ if( pTabItem->viaCoroutine ){ int regYield = pTabItem->regReturn; - sqlite3VdbeAddOp2(v, OP_Integer, pTabItem->addrFillSub-1, regYield); - pLevel->p2 = sqlite3VdbeAddOp1(v, OP_Yield, regYield); - VdbeComment((v, "next row of co-routine %s", pTabItem->pTab->zName)); - sqlite3VdbeAddOp2(v, OP_If, regYield+1, addrBrk); + sqlite3VdbeAddOp3(v, OP_InitCoroutine, regYield, 0, pTabItem->addrFillSub); + pLevel->p2 = sqlite3VdbeAddOp2(v, OP_Yield, regYield, addrBrk); + VdbeCoverage(v); + VdbeComment((v, "next row of \"%s\"", pTabItem->pTab->zName)); pLevel->op = OP_Goto; }else #ifndef SQLITE_OMIT_VIRTUALTABLE - if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){ - /* Case 0: The table is a virtual-table. Use the VFilter and VNext + if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){ + /* Case 1: The table is a virtual-table. Use the VFilter and VNext ** to access the data. */ int iReg; /* P3 Value for OP_VFilter */ int addrNotFound; - sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx; - int nConstraint = pVtabIdx->nConstraint; - struct sqlite3_index_constraint_usage *aUsage = - pVtabIdx->aConstraintUsage; - const struct sqlite3_index_constraint *aConstraint = - pVtabIdx->aConstraint; + int nConstraint = pLoop->nLTerm; sqlite3ExprCachePush(pParse); iReg = sqlite3GetTempRange(pParse, nConstraint+2); addrNotFound = pLevel->addrBrk; - for(j=1; j<=nConstraint; j++){ - for(k=0; k<nConstraint; k++){ - if( aUsage[k].argvIndex==j ){ - int iTarget = iReg+j+1; - pTerm = &pWC->a[aConstraint[k].iTermOffset]; - if( pTerm->eOperator & WO_IN ){ - codeEqualityTerm(pParse, pTerm, pLevel, k, iTarget); - addrNotFound = pLevel->addrNxt; - }else{ - sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget); - } - break; - } + for(j=0; j<nConstraint; j++){ + int iTarget = iReg+j+2; + pTerm = pLoop->aLTerm[j]; + if( pTerm==0 ) continue; + if( pTerm->eOperator & WO_IN ){ + codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget); + addrNotFound = pLevel->addrNxt; + }else{ + sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget); } - if( k==nConstraint ) break; } - sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg); - sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1); - sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, pVtabIdx->idxStr, - pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC); - pVtabIdx->needToFreeIdxStr = 0; - for(j=0; j<nConstraint; j++){ - if( aUsage[j].omit ){ - int iTerm = aConstraint[j].iTermOffset; - disableTerm(pLevel, &pWC->a[iTerm]); + sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg); + sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1); + sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, + pLoop->u.vtab.idxStr, + pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC); + VdbeCoverage(v); + pLoop->u.vtab.needFree = 0; + for(j=0; j<nConstraint && j<16; j++){ + if( (pLoop->u.vtab.omitMask>>j)&1 ){ + disableTerm(pLevel, pLoop->aLTerm[j]); } } pLevel->op = OP_VNext; pLevel->p1 = iCur; pLevel->p2 = sqlite3VdbeCurrentAddr(v); sqlite3ReleaseTempRange(pParse, iReg, nConstraint+2); - sqlite3ExprCachePop(pParse, 1); + sqlite3ExprCachePop(pParse); }else #endif /* SQLITE_OMIT_VIRTUALTABLE */ - if( pLevel->plan.wsFlags & WHERE_ROWID_EQ ){ - /* Case 1: We can directly reference a single row using an + if( (pLoop->wsFlags & WHERE_IPK)!=0 + && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0 + ){ + /* Case 2: We can directly reference a single row using an ** equality comparison against the ROWID field. Or ** we reference multiple rows using a "rowid IN (...)" ** construct. */ - iReleaseReg = sqlite3GetTempReg(pParse); - pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0); + assert( pLoop->u.btree.nEq==1 ); + pTerm = pLoop->aLTerm[0]; assert( pTerm!=0 ); assert( pTerm->pExpr!=0 ); assert( omitTable==0 ); - testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ - iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, iReleaseReg); + testcase( pTerm->wtFlags & TERM_VIRTUAL ); + iReleaseReg = ++pParse->nMem; + iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg); + if( iRowidReg!=iReleaseReg ) sqlite3ReleaseTempReg(pParse, iReleaseReg); addrNxt = pLevel->addrNxt; - sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); + sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg); + VdbeCoverage(v); sqlite3ExprCacheAffinityChange(pParse, iRowidReg, 1); sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg); VdbeComment((v, "pk")); pLevel->op = OP_Noop; - }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){ - /* Case 2: We have an inequality comparison against the ROWID field. + }else if( (pLoop->wsFlags & WHERE_IPK)!=0 + && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0 + ){ + /* Case 3: We have an inequality comparison against the ROWID field. */ int testOp = OP_Noop; int start; @@ -4299,8 +3027,11 @@ static Bitmask codeOneLoopStart( WhereTerm *pStart, *pEnd; assert( omitTable==0 ); - pStart = findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0); - pEnd = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0); + j = 0; + pStart = pEnd = 0; + if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++]; + if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++]; + assert( pStart!=0 || pEnd!=0 ); if( bRev ){ pTerm = pStart; pStart = pEnd; @@ -4314,34 +3045,42 @@ static Bitmask codeOneLoopStart( ** seek opcodes. It depends on a particular ordering of TK_xx */ const u8 aMoveOp[] = { - /* TK_GT */ OP_SeekGt, - /* TK_LE */ OP_SeekLe, - /* TK_LT */ OP_SeekLt, - /* TK_GE */ OP_SeekGe + /* TK_GT */ OP_SeekGT, + /* TK_LE */ OP_SeekLE, + /* TK_LT */ OP_SeekLT, + /* TK_GE */ OP_SeekGE }; assert( TK_LE==TK_GT+1 ); /* Make sure the ordering.. */ assert( TK_LT==TK_GT+2 ); /* ... of the TK_xx values... */ assert( TK_GE==TK_GT+3 ); /* ... is correcct. */ - testcase( pStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ + assert( (pStart->wtFlags & TERM_VNULL)==0 ); + testcase( pStart->wtFlags & TERM_VIRTUAL ); pX = pStart->pExpr; assert( pX!=0 ); - assert( pStart->leftCursor==iCur ); + testcase( pStart->leftCursor!=iCur ); /* transitive constraints */ r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp); sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1); VdbeComment((v, "pk")); + VdbeCoverageIf(v, pX->op==TK_GT); + VdbeCoverageIf(v, pX->op==TK_LE); + VdbeCoverageIf(v, pX->op==TK_LT); + VdbeCoverageIf(v, pX->op==TK_GE); sqlite3ExprCacheAffinityChange(pParse, r1, 1); sqlite3ReleaseTempReg(pParse, rTemp); disableTerm(pLevel, pStart); }else{ sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iCur, addrBrk); + VdbeCoverageIf(v, bRev==0); + VdbeCoverageIf(v, bRev!=0); } if( pEnd ){ Expr *pX; pX = pEnd->pExpr; assert( pX!=0 ); - assert( pEnd->leftCursor==iCur ); - testcase( pEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ + assert( (pEnd->wtFlags & TERM_VNULL)==0 ); + testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */ + testcase( pEnd->wtFlags & TERM_VIRTUAL ); memEndValue = ++pParse->nMem; sqlite3ExprCode(pParse, pX->pRight, memEndValue); if( pX->op==TK_LT || pX->op==TK_GT ){ @@ -4355,20 +3094,20 @@ static Bitmask codeOneLoopStart( pLevel->op = bRev ? OP_Prev : OP_Next; pLevel->p1 = iCur; pLevel->p2 = start; - if( pStart==0 && pEnd==0 ){ - pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP; - }else{ - assert( pLevel->p5==0 ); - } + assert( pLevel->p5==0 ); if( testOp!=OP_Noop ){ - iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse); + iRowidReg = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg); sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg); sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg); + VdbeCoverageIf(v, testOp==OP_Le); + VdbeCoverageIf(v, testOp==OP_Lt); + VdbeCoverageIf(v, testOp==OP_Ge); + VdbeCoverageIf(v, testOp==OP_Gt); sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL); } - }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){ - /* Case 3: A scan using an index. + }else if( pLoop->wsFlags & WHERE_INDEXED ){ + /* Case 4: A scan using an index. ** ** The WHERE clause may contain zero or more equality ** terms ("==" or "IN" operators) that refer to the N @@ -4404,20 +3143,19 @@ static Bitmask codeOneLoopStart( 0, OP_Rewind, /* 2: (!start_constraints && startEq && !bRev) */ OP_Last, /* 3: (!start_constraints && startEq && bRev) */ - OP_SeekGt, /* 4: (start_constraints && !startEq && !bRev) */ - OP_SeekLt, /* 5: (start_constraints && !startEq && bRev) */ - OP_SeekGe, /* 6: (start_constraints && startEq && !bRev) */ - OP_SeekLe /* 7: (start_constraints && startEq && bRev) */ + OP_SeekGT, /* 4: (start_constraints && !startEq && !bRev) */ + OP_SeekLT, /* 5: (start_constraints && !startEq && bRev) */ + OP_SeekGE, /* 6: (start_constraints && startEq && !bRev) */ + OP_SeekLE /* 7: (start_constraints && startEq && bRev) */ }; static const u8 aEndOp[] = { - OP_Noop, /* 0: (!end_constraints) */ - OP_IdxGE, /* 1: (end_constraints && !bRev) */ - OP_IdxLT /* 2: (end_constraints && bRev) */ + OP_IdxGE, /* 0: (end_constraints && !bRev && !endEq) */ + OP_IdxGT, /* 1: (end_constraints && !bRev && endEq) */ + OP_IdxLE, /* 2: (end_constraints && bRev && !endEq) */ + OP_IdxLT, /* 3: (end_constraints && bRev && endEq) */ }; - int nEq = pLevel->plan.nEq; /* Number of == or IN terms */ - int isMinQuery = 0; /* If this is an optimized SELECT min(x).. */ + u16 nEq = pLoop->u.btree.nEq; /* Number of == or IN terms */ int regBase; /* Base register holding constraint values */ - int r1; /* Temp register */ WhereTerm *pRangeStart = 0; /* Inequality constraint at range start */ WhereTerm *pRangeEnd = 0; /* Inequality constraint at range end */ int startEq; /* True if range start uses ==, >= or <= */ @@ -4429,11 +3167,13 @@ static Bitmask codeOneLoopStart( int nExtraReg = 0; /* Number of extra registers needed */ int op; /* Instruction opcode */ char *zStartAff; /* Affinity for start of range constraint */ - char *zEndAff; /* Affinity for end of range constraint */ + char cEndAff = 0; /* Affinity for end of range constraint */ + u8 bSeekPastNull = 0; /* True to seek past initial nulls */ + u8 bStopAtNull = 0; /* Add condition to terminate at NULLs */ - pIdx = pLevel->plan.u.pIdx; + pIdx = pLoop->u.btree.pIndex; iIdxCur = pLevel->iIdxCur; - k = (nEq==pIdx->nColumn ? -1 : pIdx->aiColumn[nEq]); + assert( nEq>=pLoop->u.btree.nSkip ); /* If this loop satisfies a sort order (pOrderBy) request that ** was passed to this function to implement a "SELECT min(x) ..." @@ -4443,52 +3183,62 @@ static Bitmask codeOneLoopStart( ** the first one after the nEq equality constraints in the index, ** this requires some special handling. */ - if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0 - && (pLevel->plan.wsFlags&WHERE_ORDERED) - && (pIdx->nColumn>nEq) + assert( pWInfo->pOrderBy==0 + || pWInfo->pOrderBy->nExpr==1 + || (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)==0 ); + if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0 + && pWInfo->nOBSat>0 + && (pIdx->nKeyCol>nEq) ){ - /* assert( pOrderBy->nExpr==1 ); */ - /* assert( pOrderBy->a[0].pExpr->iColumn==pIdx->aiColumn[nEq] ); */ - isMinQuery = 1; + assert( pLoop->u.btree.nSkip==0 ); + bSeekPastNull = 1; nExtraReg = 1; } /* Find any inequality constraint terms for the start and end ** of the range. */ - if( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ){ - pRangeEnd = findTerm(pWC, iCur, k, notReady, (WO_LT|WO_LE), pIdx); + j = nEq; + if( pLoop->wsFlags & WHERE_BTM_LIMIT ){ + pRangeStart = pLoop->aLTerm[j++]; nExtraReg = 1; } - if( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ){ - pRangeStart = findTerm(pWC, iCur, k, notReady, (WO_GT|WO_GE), pIdx); + if( pLoop->wsFlags & WHERE_TOP_LIMIT ){ + pRangeEnd = pLoop->aLTerm[j++]; nExtraReg = 1; + if( pRangeStart==0 + && (j = pIdx->aiColumn[nEq])>=0 + && pIdx->pTable->aCol[j].notNull==0 + ){ + bSeekPastNull = 1; + } } + assert( pRangeEnd==0 || (pRangeEnd->wtFlags & TERM_VNULL)==0 ); /* Generate code to evaluate all constraint terms using == or IN ** and store the values of those terms in an array of registers ** starting at regBase. */ - regBase = codeAllEqualityTerms( - pParse, pLevel, pWC, notReady, nExtraReg, &zStartAff - ); - zEndAff = sqlite3DbStrDup(pParse->db, zStartAff); + regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff); + assert( zStartAff==0 || sqlite3Strlen30(zStartAff)>=nEq ); + if( zStartAff ) cEndAff = zStartAff[nEq]; addrNxt = pLevel->addrNxt; /* If we are doing a reverse order scan on an ascending index, or ** a forward order scan on a descending index, interchange the ** start and end terms (pRangeStart and pRangeEnd). */ - if( (nEq<pIdx->nColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC)) - || (bRev && pIdx->nColumn==nEq) + if( (nEq<pIdx->nKeyCol && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC)) + || (bRev && pIdx->nKeyCol==nEq) ){ SWAP(WhereTerm *, pRangeEnd, pRangeStart); + SWAP(u8, bSeekPastNull, bStopAtNull); } - testcase( pRangeStart && pRangeStart->eOperator & WO_LE ); - testcase( pRangeStart && pRangeStart->eOperator & WO_GE ); - testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE ); - testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE ); + testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 ); + testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 ); + testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 ); + testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 ); startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE); endEq = !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE); start_constraints = pRangeStart || nEq>0; @@ -4498,8 +3248,11 @@ static Bitmask codeOneLoopStart( if( pRangeStart ){ Expr *pRight = pRangeStart->pExpr->pRight; sqlite3ExprCode(pParse, pRight, regBase+nEq); - if( (pRangeStart->wtFlags & TERM_VNULL)==0 ){ - sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt); + if( (pRangeStart->wtFlags & TERM_VNULL)==0 + && sqlite3ExprCanBeNull(pRight) + ){ + sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt); + VdbeCoverage(v); } if( zStartAff ){ if( sqlite3CompareAffinity(pRight, zStartAff[nEq])==SQLITE_AFF_NONE){ @@ -4513,23 +3266,24 @@ static Bitmask codeOneLoopStart( } } nConstraint++; - testcase( pRangeStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ - }else if( isMinQuery ){ + testcase( pRangeStart->wtFlags & TERM_VIRTUAL ); + }else if( bSeekPastNull ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq); nConstraint++; startEq = 0; start_constraints = 1; } - codeApplyAffinity(pParse, regBase, nConstraint, zStartAff); + codeApplyAffinity(pParse, regBase, nConstraint - bSeekPastNull, zStartAff); op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev]; assert( op!=0 ); - testcase( op==OP_Rewind ); - testcase( op==OP_Last ); - testcase( op==OP_SeekGt ); - testcase( op==OP_SeekGe ); - testcase( op==OP_SeekLe ); - testcase( op==OP_SeekLt ); sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint); + VdbeCoverage(v); + VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind ); + VdbeCoverageIf(v, op==OP_Last); testcase( op==OP_Last ); + VdbeCoverageIf(v, op==OP_SeekGT); testcase( op==OP_SeekGT ); + VdbeCoverageIf(v, op==OP_SeekGE); testcase( op==OP_SeekGE ); + VdbeCoverageIf(v, op==OP_SeekLE); testcase( op==OP_SeekLE ); + VdbeCoverageIf(v, op==OP_SeekLT); testcase( op==OP_SeekLT ); /* Load the value for the inequality constraint at the end of the ** range (if any). @@ -4539,67 +3293,64 @@ static Bitmask codeOneLoopStart( Expr *pRight = pRangeEnd->pExpr->pRight; sqlite3ExprCacheRemove(pParse, regBase+nEq, 1); sqlite3ExprCode(pParse, pRight, regBase+nEq); - if( (pRangeEnd->wtFlags & TERM_VNULL)==0 ){ - sqlite3ExprCodeIsNullJump(v, pRight, regBase+nEq, addrNxt); + if( (pRangeEnd->wtFlags & TERM_VNULL)==0 + && sqlite3ExprCanBeNull(pRight) + ){ + sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt); + VdbeCoverage(v); + } + if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_NONE + && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff) + ){ + codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff); } - if( zEndAff ){ - if( sqlite3CompareAffinity(pRight, zEndAff[nEq])==SQLITE_AFF_NONE){ - /* Since the comparison is to be performed with no conversions - ** applied to the operands, set the affinity to apply to pRight to - ** SQLITE_AFF_NONE. */ - zEndAff[nEq] = SQLITE_AFF_NONE; - } - if( sqlite3ExprNeedsNoAffinityChange(pRight, zEndAff[nEq]) ){ - zEndAff[nEq] = SQLITE_AFF_NONE; - } - } - codeApplyAffinity(pParse, regBase, nEq+1, zEndAff); nConstraint++; - testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */ + testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); + }else if( bStopAtNull ){ + sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq); + endEq = 0; + nConstraint++; } - sqlite3DbFree(pParse->db, zStartAff); - sqlite3DbFree(pParse->db, zEndAff); + sqlite3DbFree(db, zStartAff); /* Top of the loop body */ pLevel->p2 = sqlite3VdbeCurrentAddr(v); /* Check if the index cursor is past the end of the range. */ - op = aEndOp[(pRangeEnd || nEq) * (1 + bRev)]; - testcase( op==OP_Noop ); - testcase( op==OP_IdxGE ); - testcase( op==OP_IdxLT ); - if( op!=OP_Noop ){ + if( nConstraint ){ + op = aEndOp[bRev*2 + endEq]; sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint); - sqlite3VdbeChangeP5(v, endEq!=bRev ?1:0); - } - - /* If there are inequality constraints, check that the value - ** of the table column that the inequality contrains is not NULL. - ** If it is, jump to the next iteration of the loop. - */ - r1 = sqlite3GetTempReg(pParse); - testcase( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ); - testcase( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ); - if( (pLevel->plan.wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){ - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1); - sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont); + testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT ); + testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE ); + testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT ); + testcase( op==OP_IdxLE ); VdbeCoverageIf(v, op==OP_IdxLE ); } - sqlite3ReleaseTempReg(pParse, r1); /* Seek the table cursor, if required */ disableTerm(pLevel, pRangeStart); disableTerm(pLevel, pRangeEnd); - if( !omitTable ){ - iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse); + if( omitTable ){ + /* pIdx is a covering index. No need to access the main table. */ + }else if( HasRowid(pIdx->pTable) ){ + iRowidReg = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, iRowidReg); sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg); sqlite3VdbeAddOp2(v, OP_Seek, iCur, iRowidReg); /* Deferred seek */ + }else if( iCur!=iIdxCur ){ + Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable); + iRowidReg = sqlite3GetTempRange(pParse, pPk->nKeyCol); + for(j=0; j<pPk->nKeyCol; j++){ + k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]); + sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, iRowidReg+j); + } + sqlite3VdbeAddOp4Int(v, OP_NotFound, iCur, addrCont, + iRowidReg, pPk->nKeyCol); VdbeCoverage(v); } /* Record the instruction used to terminate the loop. Disable ** WHERE clause terms made redundant by the index range scan. */ - if( pLevel->plan.wsFlags & WHERE_UNIQUE ){ + if( pLoop->wsFlags & WHERE_ONEROW ){ pLevel->op = OP_Noop; }else if( bRev ){ pLevel->op = OP_Prev; @@ -4607,7 +3358,8 @@ static Bitmask codeOneLoopStart( pLevel->op = OP_Next; } pLevel->p1 = iIdxCur; - if( pLevel->plan.wsFlags & WHERE_COVER_SCAN ){ + pLevel->p3 = (pLoop->wsFlags&WHERE_UNQ_WANTED)!=0 ? 1:0; + if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){ pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP; }else{ assert( pLevel->p5==0 ); @@ -4615,8 +3367,8 @@ static Bitmask codeOneLoopStart( }else #ifndef SQLITE_OMIT_OR_OPTIMIZATION - if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){ - /* Case 4: Two or more separately indexed terms connected by OR + if( pLoop->wsFlags & WHERE_MULTI_OR ){ + /* Case 5: Two or more separately indexed terms connected by OR ** ** Example: ** @@ -4654,6 +3406,10 @@ static Bitmask codeOneLoopStart( ** ** B: <after the loop> ** + ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then + ** use an ephermeral index instead of a RowSet to record the primary + ** keys of the rows we have already seen. + ** */ WhereClause *pOrWc; /* The OR-clause broken out into subterms */ SrcList *pOrTab; /* Shortened table list or OR-clause generation */ @@ -4667,9 +3423,11 @@ static Bitmask codeOneLoopStart( int iRetInit; /* Address of regReturn init */ int untestedTerms = 0; /* Some terms not completely tested */ int ii; /* Loop counter */ + u16 wctrlFlags; /* Flags for sub-WHERE clause */ Expr *pAndExpr = 0; /* An ".. AND (...)" expression */ + Table *pTab = pTabItem->pTab; - pTerm = pLevel->plan.u.pTerm; + pTerm = pLoop->aLTerm[0]; assert( pTerm!=0 ); assert( pTerm->eOperator & WO_OR ); assert( (pTerm->wtFlags & TERM_ORINFO)!=0 ); @@ -4685,10 +3443,10 @@ static Bitmask codeOneLoopStart( int nNotReady; /* The number of notReady tables */ struct SrcList_item *origSrc; /* Original list of tables */ nNotReady = pWInfo->nLevel - iLevel - 1; - pOrTab = sqlite3StackAllocRaw(pParse->db, + pOrTab = sqlite3StackAllocRaw(db, sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0])); if( pOrTab==0 ) return notReady; - pOrTab->nAlloc = (i16)(nNotReady + 1); + pOrTab->nAlloc = (u8)(nNotReady + 1); pOrTab->nSrc = pOrTab->nAlloc; memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem)); origSrc = pWInfo->pTabList->a; @@ -4700,7 +3458,8 @@ static Bitmask codeOneLoopStart( } /* Initialize the rowset register to contain NULL. An SQL NULL is - ** equivalent to an empty rowset. + ** equivalent to an empty rowset. Or, create an ephermeral index + ** capable of holding primary keys in the case of a WITHOUT ROWID. ** ** Also initialize regReturn to contain the address of the instruction ** immediately following the OP_Return at the bottom of the loop. This @@ -4710,10 +3469,17 @@ static Bitmask codeOneLoopStart( ** fall through to the next instruction, just as an OP_Next does if ** called on an uninitialized cursor. */ - if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ - regRowset = ++pParse->nMem; + if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ + if( HasRowid(pTab) ){ + regRowset = ++pParse->nMem; + sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset); + }else{ + Index *pPk = sqlite3PrimaryKeyIndex(pTab); + regRowset = pParse->nTab++; + sqlite3VdbeAddOp2(v, OP_OpenEphemeral, regRowset, pPk->nKeyCol); + sqlite3VdbeSetP4KeyInfo(pParse, pPk); + } regRowid = ++pParse->nMem; - sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset); } iRetInit = sqlite3VdbeAddOp2(v, OP_Integer, 0, regReturn); @@ -4735,46 +3501,102 @@ static Bitmask codeOneLoopStart( int iTerm; for(iTerm=0; iTerm<pWC->nTerm; iTerm++){ Expr *pExpr = pWC->a[iTerm].pExpr; + if( &pWC->a[iTerm] == pTerm ) continue; if( ExprHasProperty(pExpr, EP_FromJoin) ) continue; - if( pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_ORINFO) ) continue; + testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO ); + testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL ); + if( pWC->a[iTerm].wtFlags & (TERM_ORINFO|TERM_VIRTUAL) ) continue; if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue; - pExpr = sqlite3ExprDup(pParse->db, pExpr, 0); - pAndExpr = sqlite3ExprAnd(pParse->db, pAndExpr, pExpr); + pExpr = sqlite3ExprDup(db, pExpr, 0); + pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr); } if( pAndExpr ){ pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0); } } + /* Run a separate WHERE clause for each term of the OR clause. After + ** eliminating duplicates from other WHERE clauses, the action for each + ** sub-WHERE clause is to to invoke the main loop body as a subroutine. + */ + wctrlFlags = WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY | + WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY; for(ii=0; ii<pOrWc->nTerm; ii++){ WhereTerm *pOrTerm = &pOrWc->a[ii]; if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){ - WhereInfo *pSubWInfo; /* Info for single OR-term scan */ - Expr *pOrExpr = pOrTerm->pExpr; + WhereInfo *pSubWInfo; /* Info for single OR-term scan */ + Expr *pOrExpr = pOrTerm->pExpr; /* Current OR clause term */ + int j1 = 0; /* Address of jump operation */ if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){ pAndExpr->pLeft = pOrExpr; pOrExpr = pAndExpr; } /* Loop through table entries that match term pOrTerm. */ pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0, - WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY | - WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur); - assert( pSubWInfo || pParse->nErr || pParse->db->mallocFailed ); + wctrlFlags, iCovCur); + assert( pSubWInfo || pParse->nErr || db->mallocFailed ); if( pSubWInfo ){ - WhereLevel *pLvl; + WhereLoop *pSubLoop; explainOneScan( pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0 ); - if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ - int iSet = ((ii==pOrWc->nTerm-1)?-1:ii); + /* This is the sub-WHERE clause body. First skip over + ** duplicate rows from prior sub-WHERE clauses, and record the + ** rowid (or PRIMARY KEY) for the current row so that the same + ** row will be skipped in subsequent sub-WHERE clauses. + */ + if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){ int r; - r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, - regRowid, 0); - sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, - sqlite3VdbeCurrentAddr(v)+2, r, iSet); + int iSet = ((ii==pOrWc->nTerm-1)?-1:ii); + if( HasRowid(pTab) ){ + r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0); + j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet); + VdbeCoverage(v); + }else{ + Index *pPk = sqlite3PrimaryKeyIndex(pTab); + int nPk = pPk->nKeyCol; + int iPk; + + /* Read the PK into an array of temp registers. */ + r = sqlite3GetTempRange(pParse, nPk); + for(iPk=0; iPk<nPk; iPk++){ + int iCol = pPk->aiColumn[iPk]; + sqlite3ExprCodeGetColumn(pParse, pTab, iCol, iCur, r+iPk, 0); + } + + /* Check if the temp table already contains this key. If so, + ** the row has already been included in the result set and + ** can be ignored (by jumping past the Gosub below). Otherwise, + ** insert the key into the temp table and proceed with processing + ** the row. + ** + ** Use some of the same optimizations as OP_RowSetTest: If iSet + ** is zero, assume that the key cannot already be present in + ** the temp table. And if iSet is -1, assume that there is no + ** need to insert the key into the temp table, as it will never + ** be tested for. */ + if( iSet ){ + j1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk); + VdbeCoverage(v); + } + if( iSet>=0 ){ + sqlite3VdbeAddOp3(v, OP_MakeRecord, r, nPk, regRowid); + sqlite3VdbeAddOp3(v, OP_IdxInsert, regRowset, regRowid, 0); + if( iSet ) sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT); + } + + /* Release the array of temp registers */ + sqlite3ReleaseTempRange(pParse, r, nPk); + } } + + /* Invoke the main loop body as a subroutine */ sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody); + /* Jump here (skipping the main loop body subroutine) if the + ** current sub-WHERE row is a duplicate from prior sub-WHEREs. */ + if( j1 ) sqlite3VdbeJumpHere(v, j1); + /* The pSubWInfo->untestedTerms flag means that this OR term ** contained one or more AND term from a notReady table. The ** terms from the notReady table could not be tested and will @@ -4794,13 +3616,15 @@ static Bitmask codeOneLoopStart( ** pCov to NULL to indicate that no candidate covering index will ** be available. */ - pLvl = &pSubWInfo->a[0]; - if( (pLvl->plan.wsFlags & WHERE_INDEXED)!=0 - && (pLvl->plan.wsFlags & WHERE_TEMP_INDEX)==0 - && (ii==0 || pLvl->plan.u.pIdx==pCov) + pSubLoop = pSubWInfo->a[0].pWLoop; + assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 ); + if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0 + && (ii==0 || pSubLoop->u.btree.pIndex==pCov) + && (HasRowid(pTab) || !IsPrimaryKeyIndex(pSubLoop->u.btree.pIndex)) ){ - assert( pLvl->iIdxCur==iCovCur ); - pCov = pLvl->plan.u.pIdx; + assert( pSubWInfo->a[0].iIdxCur==iCovCur ); + pCov = pSubLoop->u.btree.pIndex; + wctrlFlags |= WHERE_REOPEN_IDX; }else{ pCov = 0; } @@ -4814,45 +3638,47 @@ static Bitmask codeOneLoopStart( if( pCov ) pLevel->iIdxCur = iCovCur; if( pAndExpr ){ pAndExpr->pLeft = 0; - sqlite3ExprDelete(pParse->db, pAndExpr); + sqlite3ExprDelete(db, pAndExpr); } sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v)); sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk); sqlite3VdbeResolveLabel(v, iLoopBody); - if( pWInfo->nLevel>1 ) sqlite3StackFree(pParse->db, pOrTab); + if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab); if( !untestedTerms ) disableTerm(pLevel, pTerm); }else #endif /* SQLITE_OMIT_OR_OPTIMIZATION */ { - /* Case 5: There is no usable index. We must do a complete + /* Case 6: There is no usable index. We must do a complete ** scan of the entire table. */ static const u8 aStep[] = { OP_Next, OP_Prev }; static const u8 aStart[] = { OP_Rewind, OP_Last }; assert( bRev==0 || bRev==1 ); - assert( omitTable==0 ); - pLevel->op = aStep[bRev]; - pLevel->p1 = iCur; - pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk); - pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP; + if( pTabItem->isRecursive ){ + /* Tables marked isRecursive have only a single row that is stored in + ** a pseudo-cursor. No need to Rewind or Next such cursors. */ + pLevel->op = OP_Noop; + }else{ + pLevel->op = aStep[bRev]; + pLevel->p1 = iCur; + pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk); + VdbeCoverageIf(v, bRev==0); + VdbeCoverageIf(v, bRev!=0); + pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP; + } } - newNotReady = notReady & ~getMask(pWC->pMaskSet, iCur); /* Insert code to test every subexpression that can be completely ** computed using the current set of tables. - ** - ** IMPLEMENTATION-OF: R-49525-50935 Terms that cannot be satisfied through - ** the use of indices become tests that are evaluated against each row of - ** the relevant input tables. */ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){ Expr *pE; - testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* IMP: R-30575-11662 */ + testcase( pTerm->wtFlags & TERM_VIRTUAL ); testcase( pTerm->wtFlags & TERM_CODED ); if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue; - if( (pTerm->prereqAll & newNotReady)!=0 ){ + if( (pTerm->prereqAll & pLevel->notReady)!=0 ){ testcase( pWInfo->untestedTerms==0 && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 ); pWInfo->untestedTerms = 1; @@ -4876,22 +3702,28 @@ static Bitmask codeOneLoopStart( ** the implied "t1.a=123" constraint. */ for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){ - Expr *pE; + Expr *pE, *pEAlt; WhereTerm *pAlt; - Expr sEq; if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue; if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue; if( pTerm->leftCursor!=iCur ) continue; + if( pLevel->iLeftJoin ) continue; pE = pTerm->pExpr; assert( !ExprHasProperty(pE, EP_FromJoin) ); - assert( (pTerm->prereqRight & newNotReady)!=0 ); + assert( (pTerm->prereqRight & pLevel->notReady)!=0 ); pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0); if( pAlt==0 ) continue; if( pAlt->wtFlags & (TERM_CODED) ) continue; - VdbeNoopComment((v, "begin transitive constraint")); - sEq = *pAlt->pExpr; - sEq.pLeft = pE->pLeft; - sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL); + testcase( pAlt->eOperator & WO_EQ ); + testcase( pAlt->eOperator & WO_IN ); + VdbeModuleComment((v, "begin transitive constraint")); + pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt)); + if( pEAlt ){ + *pEAlt = *pAlt->pExpr; + pEAlt->pLeft = pE->pLeft; + sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL); + sqlite3StackFree(db, pEAlt); + } } /* For a LEFT OUTER JOIN, generate code that will record the fact that @@ -4903,10 +3735,10 @@ static Bitmask codeOneLoopStart( VdbeComment((v, "record LEFT JOIN hit")); sqlite3ExprCacheClear(pParse); for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){ - testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* IMP: R-30575-11662 */ + testcase( pTerm->wtFlags & TERM_VIRTUAL ); testcase( pTerm->wtFlags & TERM_CODED ); if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue; - if( (pTerm->prereqAll & newNotReady)!=0 ){ + if( (pTerm->prereqAll & pLevel->notReady)!=0 ){ assert( pWInfo->untestedTerms ); continue; } @@ -4915,52 +3747,2125 @@ static Bitmask codeOneLoopStart( pTerm->wtFlags |= TERM_CODED; } } - sqlite3ReleaseTempReg(pParse, iReleaseReg); - return newNotReady; + return pLevel->notReady; +} + +#if defined(WHERETRACE_ENABLED) && defined(SQLITE_ENABLE_TREE_EXPLAIN) +/* +** Generate "Explanation" text for a WhereTerm. +*/ +static void whereExplainTerm(Vdbe *v, WhereTerm *pTerm){ + char zType[4]; + memcpy(zType, "...", 4); + if( pTerm->wtFlags & TERM_VIRTUAL ) zType[0] = 'V'; + if( pTerm->eOperator & WO_EQUIV ) zType[1] = 'E'; + if( ExprHasProperty(pTerm->pExpr, EP_FromJoin) ) zType[2] = 'L'; + sqlite3ExplainPrintf(v, "%s ", zType); + sqlite3ExplainExpr(v, pTerm->pExpr); +} +#endif /* WHERETRACE_ENABLED && SQLITE_ENABLE_TREE_EXPLAIN */ + + +#ifdef WHERETRACE_ENABLED +/* +** Print a WhereLoop object for debugging purposes +*/ +static void whereLoopPrint(WhereLoop *p, WhereClause *pWC){ + WhereInfo *pWInfo = pWC->pWInfo; + int nb = 1+(pWInfo->pTabList->nSrc+7)/8; + struct SrcList_item *pItem = pWInfo->pTabList->a + p->iTab; + Table *pTab = pItem->pTab; + sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId, + p->iTab, nb, p->maskSelf, nb, p->prereq); + sqlite3DebugPrintf(" %12s", + pItem->zAlias ? pItem->zAlias : pTab->zName); + if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){ + const char *zName; + if( p->u.btree.pIndex && (zName = p->u.btree.pIndex->zName)!=0 ){ + if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){ + int i = sqlite3Strlen30(zName) - 1; + while( zName[i]!='_' ) i--; + zName += i; + } + sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq); + }else{ + sqlite3DebugPrintf("%20s",""); + } + }else{ + char *z; + if( p->u.vtab.idxStr ){ + z = sqlite3_mprintf("(%d,\"%s\",%x)", + p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask); + }else{ + z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask); + } + sqlite3DebugPrintf(" %-19s", z); + sqlite3_free(z); + } + sqlite3DebugPrintf(" f %05x N %d", p->wsFlags, p->nLTerm); + sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut); +#ifdef SQLITE_ENABLE_TREE_EXPLAIN + /* If the 0x100 bit of wheretracing is set, then show all of the constraint + ** expressions in the WhereLoop.aLTerm[] array. + */ + if( p->nLTerm && (sqlite3WhereTrace & 0x100)!=0 ){ /* WHERETRACE 0x100 */ + int i; + Vdbe *v = pWInfo->pParse->pVdbe; + sqlite3ExplainBegin(v); + for(i=0; i<p->nLTerm; i++){ + WhereTerm *pTerm = p->aLTerm[i]; + if( pTerm==0 ) continue; + sqlite3ExplainPrintf(v, " (%d) #%-2d ", i+1, (int)(pTerm-pWC->a)); + sqlite3ExplainPush(v); + whereExplainTerm(v, pTerm); + sqlite3ExplainPop(v); + sqlite3ExplainNL(v); + } + sqlite3ExplainFinish(v); + sqlite3DebugPrintf("%s", sqlite3VdbeExplanation(v)); + } +#endif +} +#endif + +/* +** Convert bulk memory into a valid WhereLoop that can be passed +** to whereLoopClear harmlessly. +*/ +static void whereLoopInit(WhereLoop *p){ + p->aLTerm = p->aLTermSpace; + p->nLTerm = 0; + p->nLSlot = ArraySize(p->aLTermSpace); + p->wsFlags = 0; } -#if defined(SQLITE_TEST) /* -** The following variable holds a text description of query plan generated -** by the most recent call to sqlite3WhereBegin(). Each call to WhereBegin -** overwrites the previous. This information is used for testing and -** analysis only. +** Clear the WhereLoop.u union. Leave WhereLoop.pLTerm intact. */ -char sqlite3_query_plan[BMS*2*40]; /* Text of the join */ -static int nQPlan = 0; /* Next free slow in _query_plan[] */ +static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){ + if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){ + if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){ + sqlite3_free(p->u.vtab.idxStr); + p->u.vtab.needFree = 0; + p->u.vtab.idxStr = 0; + }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){ + sqlite3DbFree(db, p->u.btree.pIndex->zColAff); + sqlite3KeyInfoUnref(p->u.btree.pIndex->pKeyInfo); + sqlite3DbFree(db, p->u.btree.pIndex); + p->u.btree.pIndex = 0; + } + } +} -#endif /* SQLITE_TEST */ +/* +** Deallocate internal memory used by a WhereLoop object +*/ +static void whereLoopClear(sqlite3 *db, WhereLoop *p){ + if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm); + whereLoopClearUnion(db, p); + whereLoopInit(p); +} +/* +** Increase the memory allocation for pLoop->aLTerm[] to be at least n. +*/ +static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){ + WhereTerm **paNew; + if( p->nLSlot>=n ) return SQLITE_OK; + n = (n+7)&~7; + paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n); + if( paNew==0 ) return SQLITE_NOMEM; + memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot); + if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm); + p->aLTerm = paNew; + p->nLSlot = n; + return SQLITE_OK; +} + +/* +** Transfer content from the second pLoop into the first. +*/ +static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){ + whereLoopClearUnion(db, pTo); + if( whereLoopResize(db, pTo, pFrom->nLTerm) ){ + memset(&pTo->u, 0, sizeof(pTo->u)); + return SQLITE_NOMEM; + } + memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ); + memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0])); + if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){ + pFrom->u.vtab.needFree = 0; + }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){ + pFrom->u.btree.pIndex = 0; + } + return SQLITE_OK; +} + +/* +** Delete a WhereLoop object +*/ +static void whereLoopDelete(sqlite3 *db, WhereLoop *p){ + whereLoopClear(db, p); + sqlite3DbFree(db, p); +} /* ** Free a WhereInfo structure */ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){ if( ALWAYS(pWInfo) ){ - int i; - for(i=0; i<pWInfo->nLevel; i++){ - sqlite3_index_info *pInfo = pWInfo->a[i].pIdxInfo; - if( pInfo ){ - /* assert( pInfo->needToFreeIdxStr==0 || db->mallocFailed ); */ - if( pInfo->needToFreeIdxStr ){ - sqlite3_free(pInfo->idxStr); + whereClauseClear(&pWInfo->sWC); + while( pWInfo->pLoops ){ + WhereLoop *p = pWInfo->pLoops; + pWInfo->pLoops = p->pNextLoop; + whereLoopDelete(db, p); + } + sqlite3DbFree(db, pWInfo); + } +} + +/* +** Return TRUE if both of the following are true: +** +** (1) X has the same or lower cost that Y +** (2) X is a proper subset of Y +** +** By "proper subset" we mean that X uses fewer WHERE clause terms +** than Y and that every WHERE clause term used by X is also used +** by Y. +** +** If X is a proper subset of Y then Y is a better choice and ought +** to have a lower cost. This routine returns TRUE when that cost +** relationship is inverted and needs to be adjusted. +*/ +static int whereLoopCheaperProperSubset( + const WhereLoop *pX, /* First WhereLoop to compare */ + const WhereLoop *pY /* Compare against this WhereLoop */ +){ + int i, j; + if( pX->nLTerm >= pY->nLTerm ) return 0; /* X is not a subset of Y */ + if( pX->rRun >= pY->rRun ){ + if( pX->rRun > pY->rRun ) return 0; /* X costs more than Y */ + if( pX->nOut > pY->nOut ) return 0; /* X costs more than Y */ + } + for(i=pX->nLTerm-1; i>=0; i--){ + for(j=pY->nLTerm-1; j>=0; j--){ + if( pY->aLTerm[j]==pX->aLTerm[i] ) break; + } + if( j<0 ) return 0; /* X not a subset of Y since term X[i] not used by Y */ + } + return 1; /* All conditions meet */ +} + +/* +** Try to adjust the cost of WhereLoop pTemplate upwards or downwards so +** that: +** +** (1) pTemplate costs less than any other WhereLoops that are a proper +** subset of pTemplate +** +** (2) pTemplate costs more than any other WhereLoops for which pTemplate +** is a proper subset. +** +** To say "WhereLoop X is a proper subset of Y" means that X uses fewer +** WHERE clause terms than Y and that every WHERE clause term used by X is +** also used by Y. +** +** This adjustment is omitted for SKIPSCAN loops. In a SKIPSCAN loop, the +** WhereLoop.nLTerm field is not an accurate measure of the number of WHERE +** clause terms covered, since some of the first nLTerm entries in aLTerm[] +** will be NULL (because they are skipped). That makes it more difficult +** to compare the loops. We could add extra code to do the comparison, and +** perhaps we will someday. But SKIPSCAN is sufficiently uncommon, and this +** adjustment is sufficient minor, that it is very difficult to construct +** a test case where the extra code would improve the query plan. Better +** to avoid the added complexity and just omit cost adjustments to SKIPSCAN +** loops. +*/ +static void whereLoopAdjustCost(const WhereLoop *p, WhereLoop *pTemplate){ + if( (pTemplate->wsFlags & WHERE_INDEXED)==0 ) return; + if( (pTemplate->wsFlags & WHERE_SKIPSCAN)!=0 ) return; + for(; p; p=p->pNextLoop){ + if( p->iTab!=pTemplate->iTab ) continue; + if( (p->wsFlags & WHERE_INDEXED)==0 ) continue; + if( (p->wsFlags & WHERE_SKIPSCAN)!=0 ) continue; + if( whereLoopCheaperProperSubset(p, pTemplate) ){ + /* Adjust pTemplate cost downward so that it is cheaper than its + ** subset p */ + pTemplate->rRun = p->rRun; + pTemplate->nOut = p->nOut - 1; + }else if( whereLoopCheaperProperSubset(pTemplate, p) ){ + /* Adjust pTemplate cost upward so that it is costlier than p since + ** pTemplate is a proper subset of p */ + pTemplate->rRun = p->rRun; + pTemplate->nOut = p->nOut + 1; + } + } +} + +/* +** Search the list of WhereLoops in *ppPrev looking for one that can be +** supplanted by pTemplate. +** +** Return NULL if the WhereLoop list contains an entry that can supplant +** pTemplate, in other words if pTemplate does not belong on the list. +** +** If pX is a WhereLoop that pTemplate can supplant, then return the +** link that points to pX. +** +** If pTemplate cannot supplant any existing element of the list but needs +** to be added to the list, then return a pointer to the tail of the list. +*/ +static WhereLoop **whereLoopFindLesser( + WhereLoop **ppPrev, + const WhereLoop *pTemplate +){ + WhereLoop *p; + for(p=(*ppPrev); p; ppPrev=&p->pNextLoop, p=*ppPrev){ + if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){ + /* If either the iTab or iSortIdx values for two WhereLoop are different + ** then those WhereLoops need to be considered separately. Neither is + ** a candidate to replace the other. */ + continue; + } + /* In the current implementation, the rSetup value is either zero + ** or the cost of building an automatic index (NlogN) and the NlogN + ** is the same for compatible WhereLoops. */ + assert( p->rSetup==0 || pTemplate->rSetup==0 + || p->rSetup==pTemplate->rSetup ); + + /* whereLoopAddBtree() always generates and inserts the automatic index + ** case first. Hence compatible candidate WhereLoops never have a larger + ** rSetup. Call this SETUP-INVARIANT */ + assert( p->rSetup>=pTemplate->rSetup ); + + /* Any loop using an appliation-defined index (or PRIMARY KEY or + ** UNIQUE constraint) with one or more == constraints is better + ** than an automatic index. */ + if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 + && (pTemplate->wsFlags & WHERE_INDEXED)!=0 + && (pTemplate->wsFlags & WHERE_COLUMN_EQ)!=0 + && (p->prereq & pTemplate->prereq)==pTemplate->prereq + ){ + break; + } + + /* If existing WhereLoop p is better than pTemplate, pTemplate can be + ** discarded. WhereLoop p is better if: + ** (1) p has no more dependencies than pTemplate, and + ** (2) p has an equal or lower cost than pTemplate + */ + if( (p->prereq & pTemplate->prereq)==p->prereq /* (1) */ + && p->rSetup<=pTemplate->rSetup /* (2a) */ + && p->rRun<=pTemplate->rRun /* (2b) */ + && p->nOut<=pTemplate->nOut /* (2c) */ + ){ + return 0; /* Discard pTemplate */ + } + + /* If pTemplate is always better than p, then cause p to be overwritten + ** with pTemplate. pTemplate is better than p if: + ** (1) pTemplate has no more dependences than p, and + ** (2) pTemplate has an equal or lower cost than p. + */ + if( (p->prereq & pTemplate->prereq)==pTemplate->prereq /* (1) */ + && p->rRun>=pTemplate->rRun /* (2a) */ + && p->nOut>=pTemplate->nOut /* (2b) */ + ){ + assert( p->rSetup>=pTemplate->rSetup ); /* SETUP-INVARIANT above */ + break; /* Cause p to be overwritten by pTemplate */ + } + } + return ppPrev; +} + +/* +** Insert or replace a WhereLoop entry using the template supplied. +** +** An existing WhereLoop entry might be overwritten if the new template +** is better and has fewer dependencies. Or the template will be ignored +** and no insert will occur if an existing WhereLoop is faster and has +** fewer dependencies than the template. Otherwise a new WhereLoop is +** added based on the template. +** +** If pBuilder->pOrSet is not NULL then we care about only the +** prerequisites and rRun and nOut costs of the N best loops. That +** information is gathered in the pBuilder->pOrSet object. This special +** processing mode is used only for OR clause processing. +** +** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we +** still might overwrite similar loops with the new template if the +** new template is better. Loops may be overwritten if the following +** conditions are met: +** +** (1) They have the same iTab. +** (2) They have the same iSortIdx. +** (3) The template has same or fewer dependencies than the current loop +** (4) The template has the same or lower cost than the current loop +*/ +static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){ + WhereLoop **ppPrev, *p; + WhereInfo *pWInfo = pBuilder->pWInfo; + sqlite3 *db = pWInfo->pParse->db; + + /* If pBuilder->pOrSet is defined, then only keep track of the costs + ** and prereqs. + */ + if( pBuilder->pOrSet!=0 ){ +#if WHERETRACE_ENABLED + u16 n = pBuilder->pOrSet->n; + int x = +#endif + whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun, + pTemplate->nOut); +#if WHERETRACE_ENABLED /* 0x8 */ + if( sqlite3WhereTrace & 0x8 ){ + sqlite3DebugPrintf(x?" or-%d: ":" or-X: ", n); + whereLoopPrint(pTemplate, pBuilder->pWC); + } +#endif + return SQLITE_OK; + } + + /* Look for an existing WhereLoop to replace with pTemplate + */ + whereLoopAdjustCost(pWInfo->pLoops, pTemplate); + ppPrev = whereLoopFindLesser(&pWInfo->pLoops, pTemplate); + + if( ppPrev==0 ){ + /* There already exists a WhereLoop on the list that is better + ** than pTemplate, so just ignore pTemplate */ +#if WHERETRACE_ENABLED /* 0x8 */ + if( sqlite3WhereTrace & 0x8 ){ + sqlite3DebugPrintf("ins-noop: "); + whereLoopPrint(pTemplate, pBuilder->pWC); + } +#endif + return SQLITE_OK; + }else{ + p = *ppPrev; + } + + /* If we reach this point it means that either p[] should be overwritten + ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new + ** WhereLoop and insert it. + */ +#if WHERETRACE_ENABLED /* 0x8 */ + if( sqlite3WhereTrace & 0x8 ){ + if( p!=0 ){ + sqlite3DebugPrintf("ins-del: "); + whereLoopPrint(p, pBuilder->pWC); + } + sqlite3DebugPrintf("ins-new: "); + whereLoopPrint(pTemplate, pBuilder->pWC); + } +#endif + if( p==0 ){ + /* Allocate a new WhereLoop to add to the end of the list */ + *ppPrev = p = sqlite3DbMallocRaw(db, sizeof(WhereLoop)); + if( p==0 ) return SQLITE_NOMEM; + whereLoopInit(p); + p->pNextLoop = 0; + }else{ + /* We will be overwriting WhereLoop p[]. But before we do, first + ** go through the rest of the list and delete any other entries besides + ** p[] that are also supplated by pTemplate */ + WhereLoop **ppTail = &p->pNextLoop; + WhereLoop *pToDel; + while( *ppTail ){ + ppTail = whereLoopFindLesser(ppTail, pTemplate); + if( ppTail==0 ) break; + pToDel = *ppTail; + if( pToDel==0 ) break; + *ppTail = pToDel->pNextLoop; +#if WHERETRACE_ENABLED /* 0x8 */ + if( sqlite3WhereTrace & 0x8 ){ + sqlite3DebugPrintf("ins-del: "); + whereLoopPrint(pToDel, pBuilder->pWC); + } +#endif + whereLoopDelete(db, pToDel); + } + } + whereLoopXfer(db, p, pTemplate); + if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){ + Index *pIndex = p->u.btree.pIndex; + if( pIndex && pIndex->tnum==0 ){ + p->u.btree.pIndex = 0; + } + } + return SQLITE_OK; +} + +/* +** Adjust the WhereLoop.nOut value downward to account for terms of the +** WHERE clause that reference the loop but which are not used by an +** index. +** +** In the current implementation, the first extra WHERE clause term reduces +** the number of output rows by a factor of 10 and each additional term +** reduces the number of output rows by sqrt(2). +*/ +static void whereLoopOutputAdjust(WhereClause *pWC, WhereLoop *pLoop){ + WhereTerm *pTerm, *pX; + Bitmask notAllowed = ~(pLoop->prereq|pLoop->maskSelf); + int i, j; + + if( !OptimizationEnabled(pWC->pWInfo->pParse->db, SQLITE_AdjustOutEst) ){ + return; + } + for(i=pWC->nTerm, pTerm=pWC->a; i>0; i--, pTerm++){ + if( (pTerm->wtFlags & TERM_VIRTUAL)!=0 ) break; + if( (pTerm->prereqAll & pLoop->maskSelf)==0 ) continue; + if( (pTerm->prereqAll & notAllowed)!=0 ) continue; + for(j=pLoop->nLTerm-1; j>=0; j--){ + pX = pLoop->aLTerm[j]; + if( pX==0 ) continue; + if( pX==pTerm ) break; + if( pX->iParent>=0 && (&pWC->a[pX->iParent])==pTerm ) break; + } + if( j<0 ){ + pLoop->nOut += (pTerm->truthProb<=0 ? pTerm->truthProb : -1); + } + } +} + +/* +** Adjust the cost C by the costMult facter T. This only occurs if +** compiled with -DSQLITE_ENABLE_COSTMULT +*/ +#ifdef SQLITE_ENABLE_COSTMULT +# define ApplyCostMultiplier(C,T) C += T +#else +# define ApplyCostMultiplier(C,T) +#endif + +/* +** We have so far matched pBuilder->pNew->u.btree.nEq terms of the +** index pIndex. Try to match one more. +** +** When this function is called, pBuilder->pNew->nOut contains the +** number of rows expected to be visited by filtering using the nEq +** terms only. If it is modified, this value is restored before this +** function returns. +** +** If pProbe->tnum==0, that means pIndex is a fake index used for the +** INTEGER PRIMARY KEY. +*/ +static int whereLoopAddBtreeIndex( + WhereLoopBuilder *pBuilder, /* The WhereLoop factory */ + struct SrcList_item *pSrc, /* FROM clause term being analyzed */ + Index *pProbe, /* An index on pSrc */ + LogEst nInMul /* log(Number of iterations due to IN) */ +){ + WhereInfo *pWInfo = pBuilder->pWInfo; /* WHERE analyse context */ + Parse *pParse = pWInfo->pParse; /* Parsing context */ + sqlite3 *db = pParse->db; /* Database connection malloc context */ + WhereLoop *pNew; /* Template WhereLoop under construction */ + WhereTerm *pTerm; /* A WhereTerm under consideration */ + int opMask; /* Valid operators for constraints */ + WhereScan scan; /* Iterator for WHERE terms */ + Bitmask saved_prereq; /* Original value of pNew->prereq */ + u16 saved_nLTerm; /* Original value of pNew->nLTerm */ + u16 saved_nEq; /* Original value of pNew->u.btree.nEq */ + u16 saved_nSkip; /* Original value of pNew->u.btree.nSkip */ + u32 saved_wsFlags; /* Original value of pNew->wsFlags */ + LogEst saved_nOut; /* Original value of pNew->nOut */ + int iCol; /* Index of the column in the table */ + int rc = SQLITE_OK; /* Return code */ + LogEst rLogSize; /* Logarithm of table size */ + WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */ + + pNew = pBuilder->pNew; + if( db->mallocFailed ) return SQLITE_NOMEM; + + assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 ); + assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 ); + if( pNew->wsFlags & WHERE_BTM_LIMIT ){ + opMask = WO_LT|WO_LE; + }else if( pProbe->tnum<=0 || (pSrc->jointype & JT_LEFT)!=0 ){ + opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE; + }else{ + opMask = WO_EQ|WO_IN|WO_ISNULL|WO_GT|WO_GE|WO_LT|WO_LE; + } + if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE); + + assert( pNew->u.btree.nEq<pProbe->nColumn ); + iCol = pProbe->aiColumn[pNew->u.btree.nEq]; + + pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol, + opMask, pProbe); + saved_nEq = pNew->u.btree.nEq; + saved_nSkip = pNew->u.btree.nSkip; + saved_nLTerm = pNew->nLTerm; + saved_wsFlags = pNew->wsFlags; + saved_prereq = pNew->prereq; + saved_nOut = pNew->nOut; + pNew->rSetup = 0; + rLogSize = estLog(pProbe->aiRowLogEst[0]); + + /* Consider using a skip-scan if there are no WHERE clause constraints + ** available for the left-most terms of the index, and if the average + ** number of repeats in the left-most terms is at least 18. + ** + ** The magic number 18 is selected on the basis that scanning 17 rows + ** is almost always quicker than an index seek (even though if the index + ** contains fewer than 2^17 rows we assume otherwise in other parts of + ** the code). And, even if it is not, it should not be too much slower. + ** On the other hand, the extra seeks could end up being significantly + ** more expensive. */ + assert( 42==sqlite3LogEst(18) ); + if( pTerm==0 + && saved_nEq==saved_nSkip + && saved_nEq+1<pProbe->nKeyCol + && pProbe->aiRowLogEst[saved_nEq+1]>=42 /* TUNING: Minimum for skip-scan */ + && (rc = whereLoopResize(db, pNew, pNew->nLTerm+1))==SQLITE_OK + ){ + LogEst nIter; + pNew->u.btree.nEq++; + pNew->u.btree.nSkip++; + pNew->aLTerm[pNew->nLTerm++] = 0; + pNew->wsFlags |= WHERE_SKIPSCAN; + nIter = pProbe->aiRowLogEst[saved_nEq] - pProbe->aiRowLogEst[saved_nEq+1]; + pNew->nOut -= nIter; + whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nIter + nInMul); + pNew->nOut = saved_nOut; + } + for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){ + u16 eOp = pTerm->eOperator; /* Shorthand for pTerm->eOperator */ + LogEst rCostIdx; + LogEst nOutUnadjusted; /* nOut before IN() and WHERE adjustments */ + int nIn = 0; +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + int nRecValid = pBuilder->nRecValid; +#endif + if( (eOp==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0) + && (iCol<0 || pSrc->pTab->aCol[iCol].notNull) + ){ + continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */ + } + if( pTerm->prereqRight & pNew->maskSelf ) continue; + + pNew->wsFlags = saved_wsFlags; + pNew->u.btree.nEq = saved_nEq; + pNew->nLTerm = saved_nLTerm; + if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */ + pNew->aLTerm[pNew->nLTerm++] = pTerm; + pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf; + + assert( nInMul==0 + || (pNew->wsFlags & WHERE_COLUMN_NULL)!=0 + || (pNew->wsFlags & WHERE_COLUMN_IN)!=0 + || (pNew->wsFlags & WHERE_SKIPSCAN)!=0 + ); + + if( eOp & WO_IN ){ + Expr *pExpr = pTerm->pExpr; + pNew->wsFlags |= WHERE_COLUMN_IN; + if( ExprHasProperty(pExpr, EP_xIsSelect) ){ + /* "x IN (SELECT ...)": TUNING: the SELECT returns 25 rows */ + nIn = 46; assert( 46==sqlite3LogEst(25) ); + }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){ + /* "x IN (value, value, ...)" */ + nIn = sqlite3LogEst(pExpr->x.pList->nExpr); + } + assert( nIn>0 ); /* RHS always has 2 or more terms... The parser + ** changes "x IN (?)" into "x=?". */ + + }else if( eOp & (WO_EQ) ){ + pNew->wsFlags |= WHERE_COLUMN_EQ; + if( iCol<0 || (nInMul==0 && pNew->u.btree.nEq==pProbe->nKeyCol-1) ){ + if( iCol>=0 && !IsUniqueIndex(pProbe) ){ + pNew->wsFlags |= WHERE_UNQ_WANTED; + }else{ + pNew->wsFlags |= WHERE_ONEROW; } - sqlite3DbFree(db, pInfo); } - if( pWInfo->a[i].plan.wsFlags & WHERE_TEMP_INDEX ){ - Index *pIdx = pWInfo->a[i].plan.u.pIdx; - if( pIdx ){ - sqlite3DbFree(db, pIdx->zColAff); - sqlite3DbFree(db, pIdx); + }else if( eOp & WO_ISNULL ){ + pNew->wsFlags |= WHERE_COLUMN_NULL; + }else if( eOp & (WO_GT|WO_GE) ){ + testcase( eOp & WO_GT ); + testcase( eOp & WO_GE ); + pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT; + pBtm = pTerm; + pTop = 0; + }else{ + assert( eOp & (WO_LT|WO_LE) ); + testcase( eOp & WO_LT ); + testcase( eOp & WO_LE ); + pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT; + pTop = pTerm; + pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ? + pNew->aLTerm[pNew->nLTerm-2] : 0; + } + + /* At this point pNew->nOut is set to the number of rows expected to + ** be visited by the index scan before considering term pTerm, or the + ** values of nIn and nInMul. In other words, assuming that all + ** "x IN(...)" terms are replaced with "x = ?". This block updates + ** the value of pNew->nOut to account for pTerm (but not nIn/nInMul). */ + assert( pNew->nOut==saved_nOut ); + if( pNew->wsFlags & WHERE_COLUMN_RANGE ){ + /* Adjust nOut using stat3/stat4 data. Or, if there is no stat3/stat4 + ** data, using some other estimate. */ + whereRangeScanEst(pParse, pBuilder, pBtm, pTop, pNew); + }else{ + int nEq = ++pNew->u.btree.nEq; + assert( eOp & (WO_ISNULL|WO_EQ|WO_IN) ); + + assert( pNew->nOut==saved_nOut ); + if( pTerm->truthProb<=0 && iCol>=0 ){ + assert( (eOp & WO_IN) || nIn==0 ); + testcase( eOp & WO_IN ); + pNew->nOut += pTerm->truthProb; + pNew->nOut -= nIn; + }else{ +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + tRowcnt nOut = 0; + if( nInMul==0 + && pProbe->nSample + && pNew->u.btree.nEq<=pProbe->nSampleCol + && OptimizationEnabled(db, SQLITE_Stat3) + && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect)) + ){ + Expr *pExpr = pTerm->pExpr; + if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){ + testcase( eOp & WO_EQ ); + testcase( eOp & WO_ISNULL ); + rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut); + }else{ + rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut); + } + if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK; + if( rc!=SQLITE_OK ) break; /* Jump out of the pTerm loop */ + if( nOut ){ + pNew->nOut = sqlite3LogEst(nOut); + if( pNew->nOut>saved_nOut ) pNew->nOut = saved_nOut; + pNew->nOut -= nIn; + } + } + if( nOut==0 ) +#endif + { + pNew->nOut += (pProbe->aiRowLogEst[nEq] - pProbe->aiRowLogEst[nEq-1]); + if( eOp & WO_ISNULL ){ + /* TUNING: If there is no likelihood() value, assume that a + ** "col IS NULL" expression matches twice as many rows + ** as (col=?). */ + pNew->nOut += 10; + } } } } - whereClauseClear(pWInfo->pWC); - sqlite3DbFree(db, pWInfo); + + /* Set rCostIdx to the cost of visiting selected rows in index. Add + ** it to pNew->rRun, which is currently set to the cost of the index + ** seek only. Then, if this is a non-covering index, add the cost of + ** visiting the rows in the main table. */ + rCostIdx = pNew->nOut + 1 + (15*pProbe->szIdxRow)/pSrc->pTab->szTabRow; + pNew->rRun = sqlite3LogEstAdd(rLogSize, rCostIdx); + if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){ + pNew->rRun = sqlite3LogEstAdd(pNew->rRun, pNew->nOut + 16); + } + ApplyCostMultiplier(pNew->rRun, pProbe->pTable->costMult); + + nOutUnadjusted = pNew->nOut; + pNew->rRun += nInMul + nIn; + pNew->nOut += nInMul + nIn; + whereLoopOutputAdjust(pBuilder->pWC, pNew); + rc = whereLoopInsert(pBuilder, pNew); + + if( pNew->wsFlags & WHERE_COLUMN_RANGE ){ + pNew->nOut = saved_nOut; + }else{ + pNew->nOut = nOutUnadjusted; + } + + if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 + && pNew->u.btree.nEq<pProbe->nColumn + ){ + whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn); + } + pNew->nOut = saved_nOut; +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + pBuilder->nRecValid = nRecValid; +#endif + } + pNew->prereq = saved_prereq; + pNew->u.btree.nEq = saved_nEq; + pNew->u.btree.nSkip = saved_nSkip; + pNew->wsFlags = saved_wsFlags; + pNew->nOut = saved_nOut; + pNew->nLTerm = saved_nLTerm; + return rc; +} + +/* +** Return True if it is possible that pIndex might be useful in +** implementing the ORDER BY clause in pBuilder. +** +** Return False if pBuilder does not contain an ORDER BY clause or +** if there is no way for pIndex to be useful in implementing that +** ORDER BY clause. +*/ +static int indexMightHelpWithOrderBy( + WhereLoopBuilder *pBuilder, + Index *pIndex, + int iCursor +){ + ExprList *pOB; + int ii, jj; + + if( pIndex->bUnordered ) return 0; + if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0; + for(ii=0; ii<pOB->nExpr; ii++){ + Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr); + if( pExpr->op!=TK_COLUMN ) return 0; + if( pExpr->iTable==iCursor ){ + for(jj=0; jj<pIndex->nKeyCol; jj++){ + if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1; + } + } + } + return 0; +} + +/* +** Return a bitmask where 1s indicate that the corresponding column of +** the table is used by an index. Only the first 63 columns are considered. +*/ +static Bitmask columnsInIndex(Index *pIdx){ + Bitmask m = 0; + int j; + for(j=pIdx->nColumn-1; j>=0; j--){ + int x = pIdx->aiColumn[j]; + if( x>=0 ){ + testcase( x==BMS-1 ); + testcase( x==BMS-2 ); + if( x<BMS-1 ) m |= MASKBIT(x); + } + } + return m; +} + +/* Check to see if a partial index with pPartIndexWhere can be used +** in the current query. Return true if it can be and false if not. +*/ +static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){ + int i; + WhereTerm *pTerm; + for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ + if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab) ) return 1; + } + return 0; +} + +/* +** Add all WhereLoop objects for a single table of the join where the table +** is idenfied by pBuilder->pNew->iTab. That table is guaranteed to be +** a b-tree table, not a virtual table. +** +** The costs (WhereLoop.rRun) of the b-tree loops added by this function +** are calculated as follows: +** +** For a full scan, assuming the table (or index) contains nRow rows: +** +** cost = nRow * 3.0 // full-table scan +** cost = nRow * K // scan of covering index +** cost = nRow * (K+3.0) // scan of non-covering index +** +** where K is a value between 1.1 and 3.0 set based on the relative +** estimated average size of the index and table records. +** +** For an index scan, where nVisit is the number of index rows visited +** by the scan, and nSeek is the number of seek operations required on +** the index b-tree: +** +** cost = nSeek * (log(nRow) + K * nVisit) // covering index +** cost = nSeek * (log(nRow) + (K+3.0) * nVisit) // non-covering index +** +** Normally, nSeek is 1. nSeek values greater than 1 come about if the +** WHERE clause includes "x IN (....)" terms used in place of "x=?". Or when +** implicit "x IN (SELECT x FROM tbl)" terms are added for skip-scans. +** +** The estimated values (nRow, nVisit, nSeek) often contain a large amount +** of uncertainty. For this reason, scoring is designed to pick plans that +** "do the least harm" if the estimates are inaccurate. For example, a +** log(nRow) factor is omitted from a non-covering index scan in order to +** bias the scoring in favor of using an index, since the worst-case +** performance of using an index is far better than the worst-case performance +** of a full table scan. +*/ +static int whereLoopAddBtree( + WhereLoopBuilder *pBuilder, /* WHERE clause information */ + Bitmask mExtra /* Extra prerequesites for using this table */ +){ + WhereInfo *pWInfo; /* WHERE analysis context */ + Index *pProbe; /* An index we are evaluating */ + Index sPk; /* A fake index object for the primary key */ + LogEst aiRowEstPk[2]; /* The aiRowLogEst[] value for the sPk index */ + i16 aiColumnPk = -1; /* The aColumn[] value for the sPk index */ + SrcList *pTabList; /* The FROM clause */ + struct SrcList_item *pSrc; /* The FROM clause btree term to add */ + WhereLoop *pNew; /* Template WhereLoop object */ + int rc = SQLITE_OK; /* Return code */ + int iSortIdx = 1; /* Index number */ + int b; /* A boolean value */ + LogEst rSize; /* number of rows in the table */ + LogEst rLogSize; /* Logarithm of the number of rows in the table */ + WhereClause *pWC; /* The parsed WHERE clause */ + Table *pTab; /* Table being queried */ + + pNew = pBuilder->pNew; + pWInfo = pBuilder->pWInfo; + pTabList = pWInfo->pTabList; + pSrc = pTabList->a + pNew->iTab; + pTab = pSrc->pTab; + pWC = pBuilder->pWC; + assert( !IsVirtual(pSrc->pTab) ); + + if( pSrc->pIndex ){ + /* An INDEXED BY clause specifies a particular index to use */ + pProbe = pSrc->pIndex; + }else if( !HasRowid(pTab) ){ + pProbe = pTab->pIndex; + }else{ + /* There is no INDEXED BY clause. Create a fake Index object in local + ** variable sPk to represent the rowid primary key index. Make this + ** fake index the first in a chain of Index objects with all of the real + ** indices to follow */ + Index *pFirst; /* First of real indices on the table */ + memset(&sPk, 0, sizeof(Index)); + sPk.nKeyCol = 1; + sPk.nColumn = 1; + sPk.aiColumn = &aiColumnPk; + sPk.aiRowLogEst = aiRowEstPk; + sPk.onError = OE_Replace; + sPk.pTable = pTab; + sPk.szIdxRow = pTab->szTabRow; + aiRowEstPk[0] = pTab->nRowLogEst; + aiRowEstPk[1] = 0; + pFirst = pSrc->pTab->pIndex; + if( pSrc->notIndexed==0 ){ + /* The real indices of the table are only considered if the + ** NOT INDEXED qualifier is omitted from the FROM clause */ + sPk.pNext = pFirst; + } + pProbe = &sPk; + } + rSize = pTab->nRowLogEst; + rLogSize = estLog(rSize); + +#ifndef SQLITE_OMIT_AUTOMATIC_INDEX + /* Automatic indexes */ + if( !pBuilder->pOrSet + && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0 + && pSrc->pIndex==0 + && !pSrc->viaCoroutine + && !pSrc->notIndexed + && HasRowid(pTab) + && !pSrc->isCorrelated + && !pSrc->isRecursive + ){ + /* Generate auto-index WhereLoops */ + WhereTerm *pTerm; + WhereTerm *pWCEnd = pWC->a + pWC->nTerm; + for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){ + if( pTerm->prereqRight & pNew->maskSelf ) continue; + if( termCanDriveIndex(pTerm, pSrc, 0) ){ + pNew->u.btree.nEq = 1; + pNew->u.btree.nSkip = 0; + pNew->u.btree.pIndex = 0; + pNew->nLTerm = 1; + pNew->aLTerm[0] = pTerm; + /* TUNING: One-time cost for computing the automatic index is + ** approximately 7*N*log2(N) where N is the number of rows in + ** the table being indexed. */ + pNew->rSetup = rLogSize + rSize + 28; assert( 28==sqlite3LogEst(7) ); + ApplyCostMultiplier(pNew->rSetup, pTab->costMult); + /* TUNING: Each index lookup yields 20 rows in the table. This + ** is more than the usual guess of 10 rows, since we have no way + ** of knowning how selective the index will ultimately be. It would + ** not be unreasonable to make this value much larger. */ + pNew->nOut = 43; assert( 43==sqlite3LogEst(20) ); + pNew->rRun = sqlite3LogEstAdd(rLogSize,pNew->nOut); + pNew->wsFlags = WHERE_AUTO_INDEX; + pNew->prereq = mExtra | pTerm->prereqRight; + rc = whereLoopInsert(pBuilder, pNew); + } + } + } +#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */ + + /* Loop over all indices + */ + for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){ + if( pProbe->pPartIdxWhere!=0 + && !whereUsablePartialIndex(pNew->iTab, pWC, pProbe->pPartIdxWhere) ){ + continue; /* Partial index inappropriate for this query */ + } + rSize = pProbe->aiRowLogEst[0]; + pNew->u.btree.nEq = 0; + pNew->u.btree.nSkip = 0; + pNew->nLTerm = 0; + pNew->iSortIdx = 0; + pNew->rSetup = 0; + pNew->prereq = mExtra; + pNew->nOut = rSize; + pNew->u.btree.pIndex = pProbe; + b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor); + /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */ + assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 ); + if( pProbe->tnum<=0 ){ + /* Integer primary key index */ + pNew->wsFlags = WHERE_IPK; + + /* Full table scan */ + pNew->iSortIdx = b ? iSortIdx : 0; + /* TUNING: Cost of full table scan is (N*3.0). */ + pNew->rRun = rSize + 16; + ApplyCostMultiplier(pNew->rRun, pTab->costMult); + whereLoopOutputAdjust(pWC, pNew); + rc = whereLoopInsert(pBuilder, pNew); + pNew->nOut = rSize; + if( rc ) break; + }else{ + Bitmask m; + if( pProbe->isCovering ){ + pNew->wsFlags = WHERE_IDX_ONLY | WHERE_INDEXED; + m = 0; + }else{ + m = pSrc->colUsed & ~columnsInIndex(pProbe); + pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED; + } + + /* Full scan via index */ + if( b + || !HasRowid(pTab) + || ( m==0 + && pProbe->bUnordered==0 + && (pProbe->szIdxRow<pTab->szTabRow) + && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 + && sqlite3GlobalConfig.bUseCis + && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan) + ) + ){ + pNew->iSortIdx = b ? iSortIdx : 0; + + /* The cost of visiting the index rows is N*K, where K is + ** between 1.1 and 3.0, depending on the relative sizes of the + ** index and table rows. If this is a non-covering index scan, + ** also add the cost of visiting table rows (N*3.0). */ + pNew->rRun = rSize + 1 + (15*pProbe->szIdxRow)/pTab->szTabRow; + if( m!=0 ){ + pNew->rRun = sqlite3LogEstAdd(pNew->rRun, rSize+16); + } + ApplyCostMultiplier(pNew->rRun, pTab->costMult); + whereLoopOutputAdjust(pWC, pNew); + rc = whereLoopInsert(pBuilder, pNew); + pNew->nOut = rSize; + if( rc ) break; + } + } + + rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0); +#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 + sqlite3Stat4ProbeFree(pBuilder->pRec); + pBuilder->nRecValid = 0; + pBuilder->pRec = 0; +#endif + + /* If there was an INDEXED BY clause, then only that one index is + ** considered. */ + if( pSrc->pIndex ) break; + } + return rc; +} + +#ifndef SQLITE_OMIT_VIRTUALTABLE +/* +** Add all WhereLoop objects for a table of the join identified by +** pBuilder->pNew->iTab. That table is guaranteed to be a virtual table. +*/ +static int whereLoopAddVirtual( + WhereLoopBuilder *pBuilder, /* WHERE clause information */ + Bitmask mExtra +){ + WhereInfo *pWInfo; /* WHERE analysis context */ + Parse *pParse; /* The parsing context */ + WhereClause *pWC; /* The WHERE clause */ + struct SrcList_item *pSrc; /* The FROM clause term to search */ + Table *pTab; + sqlite3 *db; + sqlite3_index_info *pIdxInfo; + struct sqlite3_index_constraint *pIdxCons; + struct sqlite3_index_constraint_usage *pUsage; + WhereTerm *pTerm; + int i, j; + int iTerm, mxTerm; + int nConstraint; + int seenIn = 0; /* True if an IN operator is seen */ + int seenVar = 0; /* True if a non-constant constraint is seen */ + int iPhase; /* 0: const w/o IN, 1: const, 2: no IN, 2: IN */ + WhereLoop *pNew; + int rc = SQLITE_OK; + + pWInfo = pBuilder->pWInfo; + pParse = pWInfo->pParse; + db = pParse->db; + pWC = pBuilder->pWC; + pNew = pBuilder->pNew; + pSrc = &pWInfo->pTabList->a[pNew->iTab]; + pTab = pSrc->pTab; + assert( IsVirtual(pTab) ); + pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy); + if( pIdxInfo==0 ) return SQLITE_NOMEM; + pNew->prereq = 0; + pNew->rSetup = 0; + pNew->wsFlags = WHERE_VIRTUALTABLE; + pNew->nLTerm = 0; + pNew->u.vtab.needFree = 0; + pUsage = pIdxInfo->aConstraintUsage; + nConstraint = pIdxInfo->nConstraint; + if( whereLoopResize(db, pNew, nConstraint) ){ + sqlite3DbFree(db, pIdxInfo); + return SQLITE_NOMEM; + } + + for(iPhase=0; iPhase<=3; iPhase++){ + if( !seenIn && (iPhase&1)!=0 ){ + iPhase++; + if( iPhase>3 ) break; + } + if( !seenVar && iPhase>1 ) break; + pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; + for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ + j = pIdxCons->iTermOffset; + pTerm = &pWC->a[j]; + switch( iPhase ){ + case 0: /* Constants without IN operator */ + pIdxCons->usable = 0; + if( (pTerm->eOperator & WO_IN)!=0 ){ + seenIn = 1; + } + if( pTerm->prereqRight!=0 ){ + seenVar = 1; + }else if( (pTerm->eOperator & WO_IN)==0 ){ + pIdxCons->usable = 1; + } + break; + case 1: /* Constants with IN operators */ + assert( seenIn ); + pIdxCons->usable = (pTerm->prereqRight==0); + break; + case 2: /* Variables without IN */ + assert( seenVar ); + pIdxCons->usable = (pTerm->eOperator & WO_IN)==0; + break; + default: /* Variables with IN */ + assert( seenVar && seenIn ); + pIdxCons->usable = 1; + break; + } + } + memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint); + if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr); + pIdxInfo->idxStr = 0; + pIdxInfo->idxNum = 0; + pIdxInfo->needToFreeIdxStr = 0; + pIdxInfo->orderByConsumed = 0; + pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2; + pIdxInfo->estimatedRows = 25; + rc = vtabBestIndex(pParse, pTab, pIdxInfo); + if( rc ) goto whereLoopAddVtab_exit; + pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; + pNew->prereq = mExtra; + mxTerm = -1; + assert( pNew->nLSlot>=nConstraint ); + for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0; + pNew->u.vtab.omitMask = 0; + for(i=0; i<nConstraint; i++, pIdxCons++){ + if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){ + j = pIdxCons->iTermOffset; + if( iTerm>=nConstraint + || j<0 + || j>=pWC->nTerm + || pNew->aLTerm[iTerm]!=0 + ){ + rc = SQLITE_ERROR; + sqlite3ErrorMsg(pParse, "%s.xBestIndex() malfunction", pTab->zName); + goto whereLoopAddVtab_exit; + } + testcase( iTerm==nConstraint-1 ); + testcase( j==0 ); + testcase( j==pWC->nTerm-1 ); + pTerm = &pWC->a[j]; + pNew->prereq |= pTerm->prereqRight; + assert( iTerm<pNew->nLSlot ); + pNew->aLTerm[iTerm] = pTerm; + if( iTerm>mxTerm ) mxTerm = iTerm; + testcase( iTerm==15 ); + testcase( iTerm==16 ); + if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm; + if( (pTerm->eOperator & WO_IN)!=0 ){ + if( pUsage[i].omit==0 ){ + /* Do not attempt to use an IN constraint if the virtual table + ** says that the equivalent EQ constraint cannot be safely omitted. + ** If we do attempt to use such a constraint, some rows might be + ** repeated in the output. */ + break; + } + /* A virtual table that is constrained by an IN clause may not + ** consume the ORDER BY clause because (1) the order of IN terms + ** is not necessarily related to the order of output terms and + ** (2) Multiple outputs from a single IN value will not merge + ** together. */ + pIdxInfo->orderByConsumed = 0; + } + } + } + if( i>=nConstraint ){ + pNew->nLTerm = mxTerm+1; + assert( pNew->nLTerm<=pNew->nLSlot ); + pNew->u.vtab.idxNum = pIdxInfo->idxNum; + pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr; + pIdxInfo->needToFreeIdxStr = 0; + pNew->u.vtab.idxStr = pIdxInfo->idxStr; + pNew->u.vtab.isOrdered = (i8)(pIdxInfo->orderByConsumed ? + pIdxInfo->nOrderBy : 0); + pNew->rSetup = 0; + pNew->rRun = sqlite3LogEstFromDouble(pIdxInfo->estimatedCost); + pNew->nOut = sqlite3LogEst(pIdxInfo->estimatedRows); + whereLoopInsert(pBuilder, pNew); + if( pNew->u.vtab.needFree ){ + sqlite3_free(pNew->u.vtab.idxStr); + pNew->u.vtab.needFree = 0; + } + } + } + +whereLoopAddVtab_exit: + if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr); + sqlite3DbFree(db, pIdxInfo); + return rc; +} +#endif /* SQLITE_OMIT_VIRTUALTABLE */ + +/* +** Add WhereLoop entries to handle OR terms. This works for either +** btrees or virtual tables. +*/ +static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){ + WhereInfo *pWInfo = pBuilder->pWInfo; + WhereClause *pWC; + WhereLoop *pNew; + WhereTerm *pTerm, *pWCEnd; + int rc = SQLITE_OK; + int iCur; + WhereClause tempWC; + WhereLoopBuilder sSubBuild; + WhereOrSet sSum, sCur; + struct SrcList_item *pItem; + + pWC = pBuilder->pWC; + if( pWInfo->wctrlFlags & WHERE_AND_ONLY ) return SQLITE_OK; + pWCEnd = pWC->a + pWC->nTerm; + pNew = pBuilder->pNew; + memset(&sSum, 0, sizeof(sSum)); + pItem = pWInfo->pTabList->a + pNew->iTab; + iCur = pItem->iCursor; + + for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){ + if( (pTerm->eOperator & WO_OR)!=0 + && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 + ){ + WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc; + WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm]; + WhereTerm *pOrTerm; + int once = 1; + int i, j; + + sSubBuild = *pBuilder; + sSubBuild.pOrderBy = 0; + sSubBuild.pOrSet = &sCur; + + for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){ + if( (pOrTerm->eOperator & WO_AND)!=0 ){ + sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc; + }else if( pOrTerm->leftCursor==iCur ){ + tempWC.pWInfo = pWC->pWInfo; + tempWC.pOuter = pWC; + tempWC.op = TK_AND; + tempWC.nTerm = 1; + tempWC.a = pOrTerm; + sSubBuild.pWC = &tempWC; + }else{ + continue; + } + sCur.n = 0; +#ifndef SQLITE_OMIT_VIRTUALTABLE + if( IsVirtual(pItem->pTab) ){ + rc = whereLoopAddVirtual(&sSubBuild, mExtra); + }else +#endif + { + rc = whereLoopAddBtree(&sSubBuild, mExtra); + } + assert( rc==SQLITE_OK || sCur.n==0 ); + if( sCur.n==0 ){ + sSum.n = 0; + break; + }else if( once ){ + whereOrMove(&sSum, &sCur); + once = 0; + }else{ + WhereOrSet sPrev; + whereOrMove(&sPrev, &sSum); + sSum.n = 0; + for(i=0; i<sPrev.n; i++){ + for(j=0; j<sCur.n; j++){ + whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq, + sqlite3LogEstAdd(sPrev.a[i].rRun, sCur.a[j].rRun), + sqlite3LogEstAdd(sPrev.a[i].nOut, sCur.a[j].nOut)); + } + } + } + } + pNew->nLTerm = 1; + pNew->aLTerm[0] = pTerm; + pNew->wsFlags = WHERE_MULTI_OR; + pNew->rSetup = 0; + pNew->iSortIdx = 0; + memset(&pNew->u, 0, sizeof(pNew->u)); + for(i=0; rc==SQLITE_OK && i<sSum.n; i++){ + /* TUNING: Currently sSum.a[i].rRun is set to the sum of the costs + ** of all sub-scans required by the OR-scan. However, due to rounding + ** errors, it may be that the cost of the OR-scan is equal to its + ** most expensive sub-scan. Add the smallest possible penalty + ** (equivalent to multiplying the cost by 1.07) to ensure that + ** this does not happen. Otherwise, for WHERE clauses such as the + ** following where there is an index on "y": + ** + ** WHERE likelihood(x=?, 0.99) OR y=? + ** + ** the planner may elect to "OR" together a full-table scan and an + ** index lookup. And other similarly odd results. */ + pNew->rRun = sSum.a[i].rRun + 1; + pNew->nOut = sSum.a[i].nOut; + pNew->prereq = sSum.a[i].prereq; + rc = whereLoopInsert(pBuilder, pNew); + } + } + } + return rc; +} + +/* +** Add all WhereLoop objects for all tables +*/ +static int whereLoopAddAll(WhereLoopBuilder *pBuilder){ + WhereInfo *pWInfo = pBuilder->pWInfo; + Bitmask mExtra = 0; + Bitmask mPrior = 0; + int iTab; + SrcList *pTabList = pWInfo->pTabList; + struct SrcList_item *pItem; + sqlite3 *db = pWInfo->pParse->db; + int nTabList = pWInfo->nLevel; + int rc = SQLITE_OK; + u8 priorJoinType = 0; + WhereLoop *pNew; + + /* Loop over the tables in the join, from left to right */ + pNew = pBuilder->pNew; + whereLoopInit(pNew); + for(iTab=0, pItem=pTabList->a; iTab<nTabList; iTab++, pItem++){ + pNew->iTab = iTab; + pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor); + if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){ + mExtra = mPrior; + } + priorJoinType = pItem->jointype; + if( IsVirtual(pItem->pTab) ){ + rc = whereLoopAddVirtual(pBuilder, mExtra); + }else{ + rc = whereLoopAddBtree(pBuilder, mExtra); + } + if( rc==SQLITE_OK ){ + rc = whereLoopAddOr(pBuilder, mExtra); + } + mPrior |= pNew->maskSelf; + if( rc || db->mallocFailed ) break; + } + whereLoopClear(db, pNew); + return rc; +} + +/* +** Examine a WherePath (with the addition of the extra WhereLoop of the 5th +** parameters) to see if it outputs rows in the requested ORDER BY +** (or GROUP BY) without requiring a separate sort operation. Return N: +** +** N>0: N terms of the ORDER BY clause are satisfied +** N==0: No terms of the ORDER BY clause are satisfied +** N<0: Unknown yet how many terms of ORDER BY might be satisfied. +** +** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as +** strict. With GROUP BY and DISTINCT the only requirement is that +** equivalent rows appear immediately adjacent to one another. GROUP BY +** and DISTINCT do not require rows to appear in any particular order as long +** as equivelent rows are grouped together. Thus for GROUP BY and DISTINCT +** the pOrderBy terms can be matched in any order. With ORDER BY, the +** pOrderBy terms must be matched in strict left-to-right order. +*/ +static i8 wherePathSatisfiesOrderBy( + WhereInfo *pWInfo, /* The WHERE clause */ + ExprList *pOrderBy, /* ORDER BY or GROUP BY or DISTINCT clause to check */ + WherePath *pPath, /* The WherePath to check */ + u16 wctrlFlags, /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */ + u16 nLoop, /* Number of entries in pPath->aLoop[] */ + WhereLoop *pLast, /* Add this WhereLoop to the end of pPath->aLoop[] */ + Bitmask *pRevMask /* OUT: Mask of WhereLoops to run in reverse order */ +){ + u8 revSet; /* True if rev is known */ + u8 rev; /* Composite sort order */ + u8 revIdx; /* Index sort order */ + u8 isOrderDistinct; /* All prior WhereLoops are order-distinct */ + u8 distinctColumns; /* True if the loop has UNIQUE NOT NULL columns */ + u8 isMatch; /* iColumn matches a term of the ORDER BY clause */ + u16 nKeyCol; /* Number of key columns in pIndex */ + u16 nColumn; /* Total number of ordered columns in the index */ + u16 nOrderBy; /* Number terms in the ORDER BY clause */ + int iLoop; /* Index of WhereLoop in pPath being processed */ + int i, j; /* Loop counters */ + int iCur; /* Cursor number for current WhereLoop */ + int iColumn; /* A column number within table iCur */ + WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */ + WhereTerm *pTerm; /* A single term of the WHERE clause */ + Expr *pOBExpr; /* An expression from the ORDER BY clause */ + CollSeq *pColl; /* COLLATE function from an ORDER BY clause term */ + Index *pIndex; /* The index associated with pLoop */ + sqlite3 *db = pWInfo->pParse->db; /* Database connection */ + Bitmask obSat = 0; /* Mask of ORDER BY terms satisfied so far */ + Bitmask obDone; /* Mask of all ORDER BY terms */ + Bitmask orderDistinctMask; /* Mask of all well-ordered loops */ + Bitmask ready; /* Mask of inner loops */ + + /* + ** We say the WhereLoop is "one-row" if it generates no more than one + ** row of output. A WhereLoop is one-row if all of the following are true: + ** (a) All index columns match with WHERE_COLUMN_EQ. + ** (b) The index is unique + ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row. + ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags. + ** + ** We say the WhereLoop is "order-distinct" if the set of columns from + ** that WhereLoop that are in the ORDER BY clause are different for every + ** row of the WhereLoop. Every one-row WhereLoop is automatically + ** order-distinct. A WhereLoop that has no columns in the ORDER BY clause + ** is not order-distinct. To be order-distinct is not quite the same as being + ** UNIQUE since a UNIQUE column or index can have multiple rows that + ** are NULL and NULL values are equivalent for the purpose of order-distinct. + ** To be order-distinct, the columns must be UNIQUE and NOT NULL. + ** + ** The rowid for a table is always UNIQUE and NOT NULL so whenever the + ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is + ** automatically order-distinct. + */ + + assert( pOrderBy!=0 ); + if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0; + + nOrderBy = pOrderBy->nExpr; + testcase( nOrderBy==BMS-1 ); + if( nOrderBy>BMS-1 ) return 0; /* Cannot optimize overly large ORDER BYs */ + isOrderDistinct = 1; + obDone = MASKBIT(nOrderBy)-1; + orderDistinctMask = 0; + ready = 0; + for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){ + if( iLoop>0 ) ready |= pLoop->maskSelf; + pLoop = iLoop<nLoop ? pPath->aLoop[iLoop] : pLast; + if( pLoop->wsFlags & WHERE_VIRTUALTABLE ){ + if( pLoop->u.vtab.isOrdered ) obSat = obDone; + break; + } + iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor; + + /* Mark off any ORDER BY term X that is a column in the table of + ** the current loop for which there is term in the WHERE + ** clause of the form X IS NULL or X=? that reference only outer + ** loops. + */ + for(i=0; i<nOrderBy; i++){ + if( MASKBIT(i) & obSat ) continue; + pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr); + if( pOBExpr->op!=TK_COLUMN ) continue; + if( pOBExpr->iTable!=iCur ) continue; + pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn, + ~ready, WO_EQ|WO_ISNULL, 0); + if( pTerm==0 ) continue; + if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){ + const char *z1, *z2; + pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr); + if( !pColl ) pColl = db->pDfltColl; + z1 = pColl->zName; + pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr); + if( !pColl ) pColl = db->pDfltColl; + z2 = pColl->zName; + if( sqlite3StrICmp(z1, z2)!=0 ) continue; + } + obSat |= MASKBIT(i); + } + + if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){ + if( pLoop->wsFlags & WHERE_IPK ){ + pIndex = 0; + nKeyCol = 0; + nColumn = 1; + }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){ + return 0; + }else{ + nKeyCol = pIndex->nKeyCol; + nColumn = pIndex->nColumn; + assert( nColumn==nKeyCol+1 || !HasRowid(pIndex->pTable) ); + assert( pIndex->aiColumn[nColumn-1]==(-1) || !HasRowid(pIndex->pTable)); + isOrderDistinct = IsUniqueIndex(pIndex); + } + + /* Loop through all columns of the index and deal with the ones + ** that are not constrained by == or IN. + */ + rev = revSet = 0; + distinctColumns = 0; + for(j=0; j<nColumn; j++){ + u8 bOnce; /* True to run the ORDER BY search loop */ + + /* Skip over == and IS NULL terms */ + if( j<pLoop->u.btree.nEq + && pLoop->u.btree.nSkip==0 + && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0 + ){ + if( i & WO_ISNULL ){ + testcase( isOrderDistinct ); + isOrderDistinct = 0; + } + continue; + } + + /* Get the column number in the table (iColumn) and sort order + ** (revIdx) for the j-th column of the index. + */ + if( pIndex ){ + iColumn = pIndex->aiColumn[j]; + revIdx = pIndex->aSortOrder[j]; + if( iColumn==pIndex->pTable->iPKey ) iColumn = -1; + }else{ + iColumn = -1; + revIdx = 0; + } + + /* An unconstrained column that might be NULL means that this + ** WhereLoop is not well-ordered + */ + if( isOrderDistinct + && iColumn>=0 + && j>=pLoop->u.btree.nEq + && pIndex->pTable->aCol[iColumn].notNull==0 + ){ + isOrderDistinct = 0; + } + + /* Find the ORDER BY term that corresponds to the j-th column + ** of the index and mark that ORDER BY term off + */ + bOnce = 1; + isMatch = 0; + for(i=0; bOnce && i<nOrderBy; i++){ + if( MASKBIT(i) & obSat ) continue; + pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr); + testcase( wctrlFlags & WHERE_GROUPBY ); + testcase( wctrlFlags & WHERE_DISTINCTBY ); + if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0; + if( pOBExpr->op!=TK_COLUMN ) continue; + if( pOBExpr->iTable!=iCur ) continue; + if( pOBExpr->iColumn!=iColumn ) continue; + if( iColumn>=0 ){ + pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr); + if( !pColl ) pColl = db->pDfltColl; + if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue; + } + isMatch = 1; + break; + } + if( isMatch && (pWInfo->wctrlFlags & WHERE_GROUPBY)==0 ){ + /* Make sure the sort order is compatible in an ORDER BY clause. + ** Sort order is irrelevant for a GROUP BY clause. */ + if( revSet ){ + if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) isMatch = 0; + }else{ + rev = revIdx ^ pOrderBy->a[i].sortOrder; + if( rev ) *pRevMask |= MASKBIT(iLoop); + revSet = 1; + } + } + if( isMatch ){ + if( iColumn<0 ){ + testcase( distinctColumns==0 ); + distinctColumns = 1; + } + obSat |= MASKBIT(i); + }else{ + /* No match found */ + if( j==0 || j<nKeyCol ){ + testcase( isOrderDistinct!=0 ); + isOrderDistinct = 0; + } + break; + } + } /* end Loop over all index columns */ + if( distinctColumns ){ + testcase( isOrderDistinct==0 ); + isOrderDistinct = 1; + } + } /* end-if not one-row */ + + /* Mark off any other ORDER BY terms that reference pLoop */ + if( isOrderDistinct ){ + orderDistinctMask |= pLoop->maskSelf; + for(i=0; i<nOrderBy; i++){ + Expr *p; + Bitmask mTerm; + if( MASKBIT(i) & obSat ) continue; + p = pOrderBy->a[i].pExpr; + mTerm = exprTableUsage(&pWInfo->sMaskSet,p); + if( mTerm==0 && !sqlite3ExprIsConstant(p) ) continue; + if( (mTerm&~orderDistinctMask)==0 ){ + obSat |= MASKBIT(i); + } + } + } + } /* End the loop over all WhereLoops from outer-most down to inner-most */ + if( obSat==obDone ) return (i8)nOrderBy; + if( !isOrderDistinct ){ + for(i=nOrderBy-1; i>0; i--){ + Bitmask m = MASKBIT(i) - 1; + if( (obSat&m)==m ) return i; + } + return 0; } + return -1; +} + + +/* +** If the WHERE_GROUPBY flag is set in the mask passed to sqlite3WhereBegin(), +** the planner assumes that the specified pOrderBy list is actually a GROUP +** BY clause - and so any order that groups rows as required satisfies the +** request. +** +** Normally, in this case it is not possible for the caller to determine +** whether or not the rows are really being delivered in sorted order, or +** just in some other order that provides the required grouping. However, +** if the WHERE_SORTBYGROUP flag is also passed to sqlite3WhereBegin(), then +** this function may be called on the returned WhereInfo object. It returns +** true if the rows really will be sorted in the specified order, or false +** otherwise. +** +** For example, assuming: +** +** CREATE INDEX i1 ON t1(x, Y); +** +** then +** +** SELECT * FROM t1 GROUP BY x,y ORDER BY x,y; -- IsSorted()==1 +** SELECT * FROM t1 GROUP BY y,x ORDER BY y,x; -- IsSorted()==0 +*/ +int sqlite3WhereIsSorted(WhereInfo *pWInfo){ + assert( pWInfo->wctrlFlags & WHERE_GROUPBY ); + assert( pWInfo->wctrlFlags & WHERE_SORTBYGROUP ); + return pWInfo->sorted; } +#ifdef WHERETRACE_ENABLED +/* For debugging use only: */ +static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){ + static char zName[65]; + int i; + for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; } + if( pLast ) zName[i++] = pLast->cId; + zName[i] = 0; + return zName; +} +#endif + +/* +** Return the cost of sorting nRow rows, assuming that the keys have +** nOrderby columns and that the first nSorted columns are already in +** order. +*/ +static LogEst whereSortingCost( + WhereInfo *pWInfo, + LogEst nRow, + int nOrderBy, + int nSorted +){ + /* TUNING: Estimated cost of a full external sort, where N is + ** the number of rows to sort is: + ** + ** cost = (3.0 * N * log(N)). + ** + ** Or, if the order-by clause has X terms but only the last Y + ** terms are out of order, then block-sorting will reduce the + ** sorting cost to: + ** + ** cost = (3.0 * N * log(N)) * (Y/X) + ** + ** The (Y/X) term is implemented using stack variable rScale + ** below. */ + LogEst rScale, rSortCost; + assert( nOrderBy>0 && 66==sqlite3LogEst(100) ); + rScale = sqlite3LogEst((nOrderBy-nSorted)*100/nOrderBy) - 66; + rSortCost = nRow + estLog(nRow) + rScale + 16; + + /* TUNING: The cost of implementing DISTINCT using a B-TREE is + ** similar but with a larger constant of proportionality. + ** Multiply by an additional factor of 3.0. */ + if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){ + rSortCost += 16; + } + + return rSortCost; +} + +/* +** Given the list of WhereLoop objects at pWInfo->pLoops, this routine +** attempts to find the lowest cost path that visits each WhereLoop +** once. This path is then loaded into the pWInfo->a[].pWLoop fields. +** +** Assume that the total number of output rows that will need to be sorted +** will be nRowEst (in the 10*log2 representation). Or, ignore sorting +** costs if nRowEst==0. +** +** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation +** error occurs. +*/ +static int wherePathSolver(WhereInfo *pWInfo, LogEst nRowEst){ + int mxChoice; /* Maximum number of simultaneous paths tracked */ + int nLoop; /* Number of terms in the join */ + Parse *pParse; /* Parsing context */ + sqlite3 *db; /* The database connection */ + int iLoop; /* Loop counter over the terms of the join */ + int ii, jj; /* Loop counters */ + int mxI = 0; /* Index of next entry to replace */ + int nOrderBy; /* Number of ORDER BY clause terms */ + LogEst mxCost = 0; /* Maximum cost of a set of paths */ + LogEst mxUnsorted = 0; /* Maximum unsorted cost of a set of path */ + int nTo, nFrom; /* Number of valid entries in aTo[] and aFrom[] */ + WherePath *aFrom; /* All nFrom paths at the previous level */ + WherePath *aTo; /* The nTo best paths at the current level */ + WherePath *pFrom; /* An element of aFrom[] that we are working on */ + WherePath *pTo; /* An element of aTo[] that we are working on */ + WhereLoop *pWLoop; /* One of the WhereLoop objects */ + WhereLoop **pX; /* Used to divy up the pSpace memory */ + LogEst *aSortCost = 0; /* Sorting and partial sorting costs */ + char *pSpace; /* Temporary memory used by this routine */ + int nSpace; /* Bytes of space allocated at pSpace */ + + pParse = pWInfo->pParse; + db = pParse->db; + nLoop = pWInfo->nLevel; + /* TUNING: For simple queries, only the best path is tracked. + ** For 2-way joins, the 5 best paths are followed. + ** For joins of 3 or more tables, track the 10 best paths */ + mxChoice = (nLoop<=1) ? 1 : (nLoop==2 ? 5 : 10); + assert( nLoop<=pWInfo->pTabList->nSrc ); + WHERETRACE(0x002, ("---- begin solver. (nRowEst=%d)\n", nRowEst)); + + /* If nRowEst is zero and there is an ORDER BY clause, ignore it. In this + ** case the purpose of this call is to estimate the number of rows returned + ** by the overall query. Once this estimate has been obtained, the caller + ** will invoke this function a second time, passing the estimate as the + ** nRowEst parameter. */ + if( pWInfo->pOrderBy==0 || nRowEst==0 ){ + nOrderBy = 0; + }else{ + nOrderBy = pWInfo->pOrderBy->nExpr; + } + + /* Allocate and initialize space for aTo, aFrom and aSortCost[] */ + nSpace = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2; + nSpace += sizeof(LogEst) * nOrderBy; + pSpace = sqlite3DbMallocRaw(db, nSpace); + if( pSpace==0 ) return SQLITE_NOMEM; + aTo = (WherePath*)pSpace; + aFrom = aTo+mxChoice; + memset(aFrom, 0, sizeof(aFrom[0])); + pX = (WhereLoop**)(aFrom+mxChoice); + for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){ + pFrom->aLoop = pX; + } + if( nOrderBy ){ + /* If there is an ORDER BY clause and it is not being ignored, set up + ** space for the aSortCost[] array. Each element of the aSortCost array + ** is either zero - meaning it has not yet been initialized - or the + ** cost of sorting nRowEst rows of data where the first X terms of + ** the ORDER BY clause are already in order, where X is the array + ** index. */ + aSortCost = (LogEst*)pX; + memset(aSortCost, 0, sizeof(LogEst) * nOrderBy); + } + assert( aSortCost==0 || &pSpace[nSpace]==(char*)&aSortCost[nOrderBy] ); + assert( aSortCost!=0 || &pSpace[nSpace]==(char*)pX ); + + /* Seed the search with a single WherePath containing zero WhereLoops. + ** + ** TUNING: Do not let the number of iterations go above 25. If the cost + ** of computing an automatic index is not paid back within the first 25 + ** rows, then do not use the automatic index. */ + aFrom[0].nRow = MIN(pParse->nQueryLoop, 46); assert( 46==sqlite3LogEst(25) ); + nFrom = 1; + assert( aFrom[0].isOrdered==0 ); + if( nOrderBy ){ + /* If nLoop is zero, then there are no FROM terms in the query. Since + ** in this case the query may return a maximum of one row, the results + ** are already in the requested order. Set isOrdered to nOrderBy to + ** indicate this. Or, if nLoop is greater than zero, set isOrdered to + ** -1, indicating that the result set may or may not be ordered, + ** depending on the loops added to the current plan. */ + aFrom[0].isOrdered = nLoop>0 ? -1 : nOrderBy; + } + + /* Compute successively longer WherePaths using the previous generation + ** of WherePaths as the basis for the next. Keep track of the mxChoice + ** best paths at each generation */ + for(iLoop=0; iLoop<nLoop; iLoop++){ + nTo = 0; + for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){ + for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){ + LogEst nOut; /* Rows visited by (pFrom+pWLoop) */ + LogEst rCost; /* Cost of path (pFrom+pWLoop) */ + LogEst rUnsorted; /* Unsorted cost of (pFrom+pWLoop) */ + i8 isOrdered = pFrom->isOrdered; /* isOrdered for (pFrom+pWLoop) */ + Bitmask maskNew; /* Mask of src visited by (..) */ + Bitmask revMask = 0; /* Mask of rev-order loops for (..) */ + + if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue; + if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue; + /* At this point, pWLoop is a candidate to be the next loop. + ** Compute its cost */ + rUnsorted = sqlite3LogEstAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow); + rUnsorted = sqlite3LogEstAdd(rUnsorted, pFrom->rUnsorted); + nOut = pFrom->nRow + pWLoop->nOut; + maskNew = pFrom->maskLoop | pWLoop->maskSelf; + if( isOrdered<0 ){ + isOrdered = wherePathSatisfiesOrderBy(pWInfo, + pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags, + iLoop, pWLoop, &revMask); + }else{ + revMask = pFrom->revLoop; + } + if( isOrdered>=0 && isOrdered<nOrderBy ){ + if( aSortCost[isOrdered]==0 ){ + aSortCost[isOrdered] = whereSortingCost( + pWInfo, nRowEst, nOrderBy, isOrdered + ); + } + rCost = sqlite3LogEstAdd(rUnsorted, aSortCost[isOrdered]); + + WHERETRACE(0x002, + ("---- sort cost=%-3d (%d/%d) increases cost %3d to %-3d\n", + aSortCost[isOrdered], (nOrderBy-isOrdered), nOrderBy, + rUnsorted, rCost)); + }else{ + rCost = rUnsorted; + } + + /* Check to see if pWLoop should be added to the set of + ** mxChoice best-so-far paths. + ** + ** First look for an existing path among best-so-far paths + ** that covers the same set of loops and has the same isOrdered + ** setting as the current path candidate. + ** + ** The term "((pTo->isOrdered^isOrdered)&0x80)==0" is equivalent + ** to (pTo->isOrdered==(-1))==(isOrdered==(-1))" for the range + ** of legal values for isOrdered, -1..64. + */ + for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){ + if( pTo->maskLoop==maskNew + && ((pTo->isOrdered^isOrdered)&0x80)==0 + ){ + testcase( jj==nTo-1 ); + break; + } + } + if( jj>=nTo ){ + /* None of the existing best-so-far paths match the candidate. */ + if( nTo>=mxChoice + && (rCost>mxCost || (rCost==mxCost && rUnsorted>=mxUnsorted)) + ){ + /* The current candidate is no better than any of the mxChoice + ** paths currently in the best-so-far buffer. So discard + ** this candidate as not viable. */ +#ifdef WHERETRACE_ENABLED /* 0x4 */ + if( sqlite3WhereTrace&0x4 ){ + sqlite3DebugPrintf("Skip %s cost=%-3d,%3d order=%c\n", + wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, + isOrdered>=0 ? isOrdered+'0' : '?'); + } +#endif + continue; + } + /* If we reach this points it means that the new candidate path + ** needs to be added to the set of best-so-far paths. */ + if( nTo<mxChoice ){ + /* Increase the size of the aTo set by one */ + jj = nTo++; + }else{ + /* New path replaces the prior worst to keep count below mxChoice */ + jj = mxI; + } + pTo = &aTo[jj]; +#ifdef WHERETRACE_ENABLED /* 0x4 */ + if( sqlite3WhereTrace&0x4 ){ + sqlite3DebugPrintf("New %s cost=%-3d,%3d order=%c\n", + wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, + isOrdered>=0 ? isOrdered+'0' : '?'); + } +#endif + }else{ + /* Control reaches here if best-so-far path pTo=aTo[jj] covers the + ** same set of loops and has the sam isOrdered setting as the + ** candidate path. Check to see if the candidate should replace + ** pTo or if the candidate should be skipped */ + if( pTo->rCost<rCost || (pTo->rCost==rCost && pTo->nRow<=nOut) ){ +#ifdef WHERETRACE_ENABLED /* 0x4 */ + if( sqlite3WhereTrace&0x4 ){ + sqlite3DebugPrintf( + "Skip %s cost=%-3d,%3d order=%c", + wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, + isOrdered>=0 ? isOrdered+'0' : '?'); + sqlite3DebugPrintf(" vs %s cost=%-3d,%d order=%c\n", + wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow, + pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?'); + } +#endif + /* Discard the candidate path from further consideration */ + testcase( pTo->rCost==rCost ); + continue; + } + testcase( pTo->rCost==rCost+1 ); + /* Control reaches here if the candidate path is better than the + ** pTo path. Replace pTo with the candidate. */ +#ifdef WHERETRACE_ENABLED /* 0x4 */ + if( sqlite3WhereTrace&0x4 ){ + sqlite3DebugPrintf( + "Update %s cost=%-3d,%3d order=%c", + wherePathName(pFrom, iLoop, pWLoop), rCost, nOut, + isOrdered>=0 ? isOrdered+'0' : '?'); + sqlite3DebugPrintf(" was %s cost=%-3d,%3d order=%c\n", + wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow, + pTo->isOrdered>=0 ? pTo->isOrdered+'0' : '?'); + } +#endif + } + /* pWLoop is a winner. Add it to the set of best so far */ + pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf; + pTo->revLoop = revMask; + pTo->nRow = nOut; + pTo->rCost = rCost; + pTo->rUnsorted = rUnsorted; + pTo->isOrdered = isOrdered; + memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop); + pTo->aLoop[iLoop] = pWLoop; + if( nTo>=mxChoice ){ + mxI = 0; + mxCost = aTo[0].rCost; + mxUnsorted = aTo[0].nRow; + for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){ + if( pTo->rCost>mxCost + || (pTo->rCost==mxCost && pTo->rUnsorted>mxUnsorted) + ){ + mxCost = pTo->rCost; + mxUnsorted = pTo->rUnsorted; + mxI = jj; + } + } + } + } + } + +#ifdef WHERETRACE_ENABLED /* >=2 */ + if( sqlite3WhereTrace>=2 ){ + sqlite3DebugPrintf("---- after round %d ----\n", iLoop); + for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){ + sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c", + wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow, + pTo->isOrdered>=0 ? (pTo->isOrdered+'0') : '?'); + if( pTo->isOrdered>0 ){ + sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop); + }else{ + sqlite3DebugPrintf("\n"); + } + } + } +#endif + + /* Swap the roles of aFrom and aTo for the next generation */ + pFrom = aTo; + aTo = aFrom; + aFrom = pFrom; + nFrom = nTo; + } + + if( nFrom==0 ){ + sqlite3ErrorMsg(pParse, "no query solution"); + sqlite3DbFree(db, pSpace); + return SQLITE_ERROR; + } + + /* Find the lowest cost path. pFrom will be left pointing to that path */ + pFrom = aFrom; + for(ii=1; ii<nFrom; ii++){ + if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii]; + } + assert( pWInfo->nLevel==nLoop ); + /* Load the lowest cost path into pWInfo */ + for(iLoop=0; iLoop<nLoop; iLoop++){ + WhereLevel *pLevel = pWInfo->a + iLoop; + pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop]; + pLevel->iFrom = pWLoop->iTab; + pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor; + } + if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0 + && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0 + && pWInfo->eDistinct==WHERE_DISTINCT_NOOP + && nRowEst + ){ + Bitmask notUsed; + int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom, + WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], ¬Used); + if( rc==pWInfo->pResultSet->nExpr ){ + pWInfo->eDistinct = WHERE_DISTINCT_ORDERED; + } + } + if( pWInfo->pOrderBy ){ + if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){ + if( pFrom->isOrdered==pWInfo->pOrderBy->nExpr ){ + pWInfo->eDistinct = WHERE_DISTINCT_ORDERED; + } + }else{ + pWInfo->nOBSat = pFrom->isOrdered; + if( pWInfo->nOBSat<0 ) pWInfo->nOBSat = 0; + pWInfo->revMask = pFrom->revLoop; + } + if( (pWInfo->wctrlFlags & WHERE_SORTBYGROUP) + && pWInfo->nOBSat==pWInfo->pOrderBy->nExpr + ){ + Bitmask notUsed = 0; + int nOrder = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pOrderBy, + pFrom, 0, nLoop-1, pFrom->aLoop[nLoop-1], ¬Used + ); + assert( pWInfo->sorted==0 ); + pWInfo->sorted = (nOrder==pWInfo->pOrderBy->nExpr); + } + } + + + pWInfo->nRowOut = pFrom->nRow; + + /* Free temporary memory and return success */ + sqlite3DbFree(db, pSpace); + return SQLITE_OK; +} + +/* +** Most queries use only a single table (they are not joins) and have +** simple == constraints against indexed fields. This routine attempts +** to plan those simple cases using much less ceremony than the +** general-purpose query planner, and thereby yield faster sqlite3_prepare() +** times for the common case. +** +** Return non-zero on success, if this query can be handled by this +** no-frills query planner. Return zero if this query needs the +** general-purpose query planner. +*/ +static int whereShortCut(WhereLoopBuilder *pBuilder){ + WhereInfo *pWInfo; + struct SrcList_item *pItem; + WhereClause *pWC; + WhereTerm *pTerm; + WhereLoop *pLoop; + int iCur; + int j; + Table *pTab; + Index *pIdx; + + pWInfo = pBuilder->pWInfo; + if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0; + assert( pWInfo->pTabList->nSrc>=1 ); + pItem = pWInfo->pTabList->a; + pTab = pItem->pTab; + if( IsVirtual(pTab) ) return 0; + if( pItem->zIndex ) return 0; + iCur = pItem->iCursor; + pWC = &pWInfo->sWC; + pLoop = pBuilder->pNew; + pLoop->wsFlags = 0; + pLoop->u.btree.nSkip = 0; + pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0); + if( pTerm ){ + pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW; + pLoop->aLTerm[0] = pTerm; + pLoop->nLTerm = 1; + pLoop->u.btree.nEq = 1; + /* TUNING: Cost of a rowid lookup is 10 */ + pLoop->rRun = 33; /* 33==sqlite3LogEst(10) */ + }else{ + for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ + assert( pLoop->aLTermSpace==pLoop->aLTerm ); + assert( ArraySize(pLoop->aLTermSpace)==4 ); + if( !IsUniqueIndex(pIdx) + || pIdx->pPartIdxWhere!=0 + || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) + ) continue; + for(j=0; j<pIdx->nKeyCol; j++){ + pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx); + if( pTerm==0 ) break; + pLoop->aLTerm[j] = pTerm; + } + if( j!=pIdx->nKeyCol ) continue; + pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED; + if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){ + pLoop->wsFlags |= WHERE_IDX_ONLY; + } + pLoop->nLTerm = j; + pLoop->u.btree.nEq = j; + pLoop->u.btree.pIndex = pIdx; + /* TUNING: Cost of a unique index lookup is 15 */ + pLoop->rRun = 39; /* 39==sqlite3LogEst(15) */ + break; + } + } + if( pLoop->wsFlags ){ + pLoop->nOut = (LogEst)1; + pWInfo->a[0].pWLoop = pLoop; + pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur); + pWInfo->a[0].iTabCur = iCur; + pWInfo->nRowOut = 1; + if( pWInfo->pOrderBy ) pWInfo->nOBSat = pWInfo->pOrderBy->nExpr; + if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){ + pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE; + } +#ifdef SQLITE_DEBUG + pLoop->cId = '0'; +#endif + return 1; + } + return 0; +} /* ** Generate the beginning of the loop used for WHERE clause processing. @@ -5037,25 +5942,25 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){ ** ** ORDER BY CLAUSE PROCESSING ** -** pOrderBy is a pointer to the ORDER BY clause of a SELECT statement, +** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause +** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement ** if there is one. If there is no ORDER BY clause or if this routine ** is called from an UPDATE or DELETE statement, then pOrderBy is NULL. ** -** If an index can be used so that the natural output order of the table -** scan is correct for the ORDER BY clause, then that index is used and -** the returned WhereInfo.nOBSat field is set to pOrderBy->nExpr. This -** is an optimization that prevents an unnecessary sort of the result set -** if an index appropriate for the ORDER BY clause already exists. -** -** If the where clause loops cannot be arranged to provide the correct -** output order, then WhereInfo.nOBSat is 0. +** The iIdxCur parameter is the cursor number of an index. If +** WHERE_ONETABLE_ONLY is set, iIdxCur is the cursor number of an index +** to use for OR clause processing. The WHERE clause should use this +** specific cursor. If WHERE_ONEPASS_DESIRED is set, then iIdxCur is +** the first cursor in an array of cursors for all indices. iIdxCur should +** be used to compute the appropriate cursor depending on which index is +** used. */ WhereInfo *sqlite3WhereBegin( Parse *pParse, /* The parser context */ - SrcList *pTabList, /* A list of all tables to be scanned */ + SrcList *pTabList, /* FROM clause: A list of all tables to be scanned */ Expr *pWhere, /* The WHERE clause */ - ExprList *pOrderBy, /* An ORDER BY clause, or NULL */ - ExprList *pDistinct, /* The select-list for DISTINCT queries - or NULL */ + ExprList *pOrderBy, /* An ORDER BY (or GROUP BY) clause, or NULL */ + ExprList *pResultSet, /* Result set of the query */ u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */ int iIdxCur /* If WHERE_ONETABLE_ONLY is set, index cursor number */ ){ @@ -5064,18 +5969,29 @@ WhereInfo *sqlite3WhereBegin( WhereInfo *pWInfo; /* Will become the return value of this function */ Vdbe *v = pParse->pVdbe; /* The virtual database engine */ Bitmask notReady; /* Cursors that are not yet positioned */ - WhereBestIdx sWBI; /* Best index search context */ + WhereLoopBuilder sWLB; /* The WhereLoop builder */ WhereMaskSet *pMaskSet; /* The expression mask set */ WhereLevel *pLevel; /* A single level in pWInfo->a[] */ - int iFrom; /* First unused FROM clause element */ - int andFlags; /* AND-ed combination of all pWC->a[].wtFlags */ + WhereLoop *pLoop; /* Pointer to a single WhereLoop object */ int ii; /* Loop counter */ sqlite3 *db; /* Database connection */ + int rc; /* Return code */ /* Variable initialization */ - memset(&sWBI, 0, sizeof(sWBI)); - sWBI.pParse = pParse; + db = pParse->db; + memset(&sWLB, 0, sizeof(sWLB)); + + /* An ORDER/GROUP BY clause of more than 63 terms cannot be optimized */ + testcase( pOrderBy && pOrderBy->nExpr==BMS-1 ); + if( pOrderBy && pOrderBy->nExpr>=BMS ) pOrderBy = 0; + sWLB.pOrderBy = pOrderBy; + + /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via + ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */ + if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){ + wctrlFlags &= ~WHERE_WANT_DISTINCT; + } /* The number of tables in the FROM clause is limited by the number of ** bits in a Bitmask @@ -5100,46 +6016,57 @@ WhereInfo *sqlite3WhereBegin( ** field (type Bitmask) it must be aligned on an 8-byte boundary on ** some architectures. Hence the ROUND8() below. */ - db = pParse->db; nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel)); - pWInfo = sqlite3DbMallocZero(db, - nByteWInfo + - sizeof(WhereClause) + - sizeof(WhereMaskSet) - ); + pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop)); if( db->mallocFailed ){ sqlite3DbFree(db, pWInfo); pWInfo = 0; goto whereBeginError; } + pWInfo->aiCurOnePass[0] = pWInfo->aiCurOnePass[1] = -1; pWInfo->nLevel = nTabList; pWInfo->pParse = pParse; pWInfo->pTabList = pTabList; - pWInfo->iBreak = sqlite3VdbeMakeLabel(v); - pWInfo->pWC = sWBI.pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo]; + pWInfo->pOrderBy = pOrderBy; + pWInfo->pResultSet = pResultSet; + pWInfo->iBreak = pWInfo->iContinue = sqlite3VdbeMakeLabel(v); pWInfo->wctrlFlags = wctrlFlags; pWInfo->savedNQueryLoop = pParse->nQueryLoop; - pMaskSet = (WhereMaskSet*)&sWBI.pWC[1]; - sWBI.aLevel = pWInfo->a; - - /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via - ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */ - if( OptimizationDisabled(db, SQLITE_DistinctOpt) ) pDistinct = 0; + pMaskSet = &pWInfo->sMaskSet; + sWLB.pWInfo = pWInfo; + sWLB.pWC = &pWInfo->sWC; + sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo); + assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) ); + whereLoopInit(sWLB.pNew); +#ifdef SQLITE_DEBUG + sWLB.pNew->cId = '*'; +#endif /* Split the WHERE clause into separate subexpressions where each ** subexpression is separated by an AND operator. */ initMaskSet(pMaskSet); - whereClauseInit(sWBI.pWC, pParse, pMaskSet, wctrlFlags); - sqlite3ExprCodeConstants(pParse, pWhere); - whereSplit(sWBI.pWC, pWhere, TK_AND); /* IMP: R-15842-53296 */ + whereClauseInit(&pWInfo->sWC, pWInfo); + whereSplit(&pWInfo->sWC, pWhere, TK_AND); /* Special case: a WHERE clause that is constant. Evaluate the ** expression and either jump over all of the code or fall thru. */ - if( pWhere && (nTabList==0 || sqlite3ExprIsConstantNotJoin(pWhere)) ){ - sqlite3ExprIfFalse(pParse, pWhere, pWInfo->iBreak, SQLITE_JUMPIFNULL); - pWhere = 0; + for(ii=0; ii<sWLB.pWC->nTerm; ii++){ + if( nTabList==0 || sqlite3ExprIsConstantNotJoin(sWLB.pWC->a[ii].pExpr) ){ + sqlite3ExprIfFalse(pParse, sWLB.pWC->a[ii].pExpr, pWInfo->iBreak, + SQLITE_JUMPIFNULL); + sWLB.pWC->a[ii].wtFlags |= TERM_CODED; + } + } + + /* Special case: No FROM clause + */ + if( nTabList==0 ){ + if( pOrderBy ) pWInfo->nOBSat = pOrderBy->nExpr; + if( wctrlFlags & WHERE_WANT_DISTINCT ){ + pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE; + } } /* Assign a bit from the bitmask to every term in the FROM clause. @@ -5177,306 +6104,151 @@ WhereInfo *sqlite3WhereBegin( ** want to analyze these virtual terms, so start analyzing at the end ** and work forward so that the added virtual terms are never processed. */ - exprAnalyzeAll(pTabList, sWBI.pWC); + exprAnalyzeAll(pTabList, &pWInfo->sWC); if( db->mallocFailed ){ goto whereBeginError; } - /* Check if the DISTINCT qualifier, if there is one, is redundant. - ** If it is, then set pDistinct to NULL and WhereInfo.eDistinct to - ** WHERE_DISTINCT_UNIQUE to tell the caller to ignore the DISTINCT. - */ - if( pDistinct && isDistinctRedundant(pParse, pTabList, sWBI.pWC, pDistinct) ){ - pDistinct = 0; - pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE; + if( wctrlFlags & WHERE_WANT_DISTINCT ){ + if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){ + /* The DISTINCT marking is pointless. Ignore it. */ + pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE; + }else if( pOrderBy==0 ){ + /* Try to ORDER BY the result set to make distinct processing easier */ + pWInfo->wctrlFlags |= WHERE_DISTINCTBY; + pWInfo->pOrderBy = pResultSet; + } } - /* Chose the best index to use for each table in the FROM clause. - ** - ** This loop fills in the following fields: - ** - ** pWInfo->a[].pIdx The index to use for this level of the loop. - ** pWInfo->a[].wsFlags WHERE_xxx flags associated with pIdx - ** pWInfo->a[].nEq The number of == and IN constraints - ** pWInfo->a[].iFrom Which term of the FROM clause is being coded - ** pWInfo->a[].iTabCur The VDBE cursor for the database table - ** pWInfo->a[].iIdxCur The VDBE cursor for the index - ** pWInfo->a[].pTerm When wsFlags==WO_OR, the OR-clause term - ** - ** This loop also figures out the nesting order of tables in the FROM - ** clause. - */ - sWBI.notValid = ~(Bitmask)0; - sWBI.pOrderBy = pOrderBy; - sWBI.n = nTabList; - sWBI.pDistinct = pDistinct; - andFlags = ~0; - WHERETRACE(("*** Optimizer Start ***\n")); - for(sWBI.i=iFrom=0, pLevel=pWInfo->a; sWBI.i<nTabList; sWBI.i++, pLevel++){ - WhereCost bestPlan; /* Most efficient plan seen so far */ - Index *pIdx; /* Index for FROM table at pTabItem */ - int j; /* For looping over FROM tables */ - int bestJ = -1; /* The value of j */ - Bitmask m; /* Bitmask value for j or bestJ */ - int isOptimal; /* Iterator for optimal/non-optimal search */ - int ckOptimal; /* Do the optimal scan check */ - int nUnconstrained; /* Number tables without INDEXED BY */ - Bitmask notIndexed; /* Mask of tables that cannot use an index */ - - memset(&bestPlan, 0, sizeof(bestPlan)); - bestPlan.rCost = SQLITE_BIG_DBL; - WHERETRACE(("*** Begin search for loop %d ***\n", sWBI.i)); - - /* Loop through the remaining entries in the FROM clause to find the - ** next nested loop. The loop tests all FROM clause entries - ** either once or twice. - ** - ** The first test is always performed if there are two or more entries - ** remaining and never performed if there is only one FROM clause entry - ** to choose from. The first test looks for an "optimal" scan. In - ** this context an optimal scan is one that uses the same strategy - ** for the given FROM clause entry as would be selected if the entry - ** were used as the innermost nested loop. In other words, a table - ** is chosen such that the cost of running that table cannot be reduced - ** by waiting for other tables to run first. This "optimal" test works - ** by first assuming that the FROM clause is on the inner loop and finding - ** its query plan, then checking to see if that query plan uses any - ** other FROM clause terms that are sWBI.notValid. If no notValid terms - ** are used then the "optimal" query plan works. - ** - ** Note that the WhereCost.nRow parameter for an optimal scan might - ** not be as small as it would be if the table really were the innermost - ** join. The nRow value can be reduced by WHERE clause constraints - ** that do not use indices. But this nRow reduction only happens if the - ** table really is the innermost join. - ** - ** The second loop iteration is only performed if no optimal scan - ** strategies were found by the first iteration. This second iteration - ** is used to search for the lowest cost scan overall. - ** - ** Without the optimal scan step (the first iteration) a suboptimal - ** plan might be chosen for queries like this: - ** - ** CREATE TABLE t1(a, b); - ** CREATE TABLE t2(c, d); - ** SELECT * FROM t2, t1 WHERE t2.rowid = t1.a; - ** - ** The best strategy is to iterate through table t1 first. However it - ** is not possible to determine this with a simple greedy algorithm. - ** Since the cost of a linear scan through table t2 is the same - ** as the cost of a linear scan through table t1, a simple greedy - ** algorithm may choose to use t2 for the outer loop, which is a much - ** costlier approach. - */ - nUnconstrained = 0; - notIndexed = 0; - - /* The optimal scan check only occurs if there are two or more tables - ** available to be reordered */ - if( iFrom==nTabList-1 ){ - ckOptimal = 0; /* Common case of just one table in the FROM clause */ - }else{ - ckOptimal = -1; - for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){ - m = getMask(pMaskSet, sWBI.pSrc->iCursor); - if( (m & sWBI.notValid)==0 ){ - if( j==iFrom ) iFrom++; - continue; - } - if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ) break; - if( ++ckOptimal ) break; - if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break; + /* Construct the WhereLoop objects */ + WHERETRACE(0xffff,("*** Optimizer Start ***\n")); + /* Display all terms of the WHERE clause */ +#if defined(WHERETRACE_ENABLED) && defined(SQLITE_ENABLE_TREE_EXPLAIN) + if( sqlite3WhereTrace & 0x100 ){ + int i; + Vdbe *v = pParse->pVdbe; + sqlite3ExplainBegin(v); + for(i=0; i<sWLB.pWC->nTerm; i++){ + sqlite3ExplainPrintf(v, "#%-2d ", i); + sqlite3ExplainPush(v); + whereExplainTerm(v, &sWLB.pWC->a[i]); + sqlite3ExplainPop(v); + sqlite3ExplainNL(v); + } + sqlite3ExplainFinish(v); + sqlite3DebugPrintf("%s", sqlite3VdbeExplanation(v)); + } +#endif + if( nTabList!=1 || whereShortCut(&sWLB)==0 ){ + rc = whereLoopAddAll(&sWLB); + if( rc ) goto whereBeginError; + + /* Display all of the WhereLoop objects if wheretrace is enabled */ +#ifdef WHERETRACE_ENABLED /* !=0 */ + if( sqlite3WhereTrace ){ + WhereLoop *p; + int i; + static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz" + "ABCDEFGHIJKLMNOPQRSTUVWYXZ"; + for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){ + p->cId = zLabel[i%sizeof(zLabel)]; + whereLoopPrint(p, sWLB.pWC); } } - assert( ckOptimal==0 || ckOptimal==1 ); - - for(isOptimal=ckOptimal; isOptimal>=0 && bestJ<0; isOptimal--){ - for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){ - if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ){ - /* This break and one like it in the ckOptimal computation loop - ** above prevent table reordering across LEFT and CROSS JOINs. - ** The LEFT JOIN case is necessary for correctness. The prohibition - ** against reordering across a CROSS JOIN is an SQLite feature that - ** allows the developer to control table reordering */ - break; - } - m = getMask(pMaskSet, sWBI.pSrc->iCursor); - if( (m & sWBI.notValid)==0 ){ - assert( j>iFrom ); - continue; - } - sWBI.notReady = (isOptimal ? m : sWBI.notValid); - if( sWBI.pSrc->pIndex==0 ) nUnconstrained++; - - WHERETRACE((" === trying table %d (%s) with isOptimal=%d ===\n", - j, sWBI.pSrc->pTab->zName, isOptimal)); - assert( sWBI.pSrc->pTab ); -#ifndef SQLITE_OMIT_VIRTUALTABLE - if( IsVirtual(sWBI.pSrc->pTab) ){ - sWBI.ppIdxInfo = &pWInfo->a[j].pIdxInfo; - bestVirtualIndex(&sWBI); - }else #endif - { - bestBtreeIndex(&sWBI); - } - assert( isOptimal || (sWBI.cost.used&sWBI.notValid)==0 ); - - /* If an INDEXED BY clause is present, then the plan must use that - ** index if it uses any index at all */ - assert( sWBI.pSrc->pIndex==0 - || (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 - || sWBI.cost.plan.u.pIdx==sWBI.pSrc->pIndex ); - - if( isOptimal && (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){ - notIndexed |= m; - } - if( isOptimal ){ - pWInfo->a[j].rOptCost = sWBI.cost.rCost; - }else if( ckOptimal ){ - /* If two or more tables have nearly the same outer loop cost, but - ** very different inner loop (optimal) cost, we want to choose - ** for the outer loop that table which benefits the least from - ** being in the inner loop. The following code scales the - ** outer loop cost estimate to accomplish that. */ - WHERETRACE((" scaling cost from %.1f to %.1f\n", - sWBI.cost.rCost, - sWBI.cost.rCost/pWInfo->a[j].rOptCost)); - sWBI.cost.rCost /= pWInfo->a[j].rOptCost; - } - - /* Conditions under which this table becomes the best so far: - ** - ** (1) The table must not depend on other tables that have not - ** yet run. (In other words, it must not depend on tables - ** in inner loops.) - ** - ** (2) (This rule was removed on 2012-11-09. The scaling of the - ** cost using the optimal scan cost made this rule obsolete.) - ** - ** (3) All tables have an INDEXED BY clause or this table lacks an - ** INDEXED BY clause or this table uses the specific - ** index specified by its INDEXED BY clause. This rule ensures - ** that a best-so-far is always selected even if an impossible - ** combination of INDEXED BY clauses are given. The error - ** will be detected and relayed back to the application later. - ** The NEVER() comes about because rule (2) above prevents - ** An indexable full-table-scan from reaching rule (3). - ** - ** (4) The plan cost must be lower than prior plans, where "cost" - ** is defined by the compareCost() function above. - */ - if( (sWBI.cost.used&sWBI.notValid)==0 /* (1) */ - && (nUnconstrained==0 || sWBI.pSrc->pIndex==0 /* (3) */ - || NEVER((sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0)) - && (bestJ<0 || compareCost(&sWBI.cost, &bestPlan)) /* (4) */ - ){ - WHERETRACE((" === table %d (%s) is best so far\n" - " cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=%08x\n", - j, sWBI.pSrc->pTab->zName, - sWBI.cost.rCost, sWBI.cost.plan.nRow, - sWBI.cost.plan.nOBSat, sWBI.cost.plan.wsFlags)); - bestPlan = sWBI.cost; - bestJ = j; - } - - /* In a join like "w JOIN x LEFT JOIN y JOIN z" make sure that - ** table y (and not table z) is always the next inner loop inside - ** of table x. */ - if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break; - } + + wherePathSolver(pWInfo, 0); + if( db->mallocFailed ) goto whereBeginError; + if( pWInfo->pOrderBy ){ + wherePathSolver(pWInfo, pWInfo->nRowOut+1); + if( db->mallocFailed ) goto whereBeginError; } - assert( bestJ>=0 ); - assert( sWBI.notValid & getMask(pMaskSet, pTabList->a[bestJ].iCursor) ); - assert( bestJ==iFrom || (pTabList->a[iFrom].jointype & JT_LEFT)==0 ); - testcase( bestJ>iFrom && (pTabList->a[iFrom].jointype & JT_CROSS)!=0 ); - testcase( bestJ>iFrom && bestJ<nTabList-1 - && (pTabList->a[bestJ+1].jointype & JT_LEFT)!=0 ); - WHERETRACE(("*** Optimizer selects table %d (%s) for loop %d with:\n" - " cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=0x%08x\n", - bestJ, pTabList->a[bestJ].pTab->zName, - pLevel-pWInfo->a, bestPlan.rCost, bestPlan.plan.nRow, - bestPlan.plan.nOBSat, bestPlan.plan.wsFlags)); - if( (bestPlan.plan.wsFlags & WHERE_DISTINCT)!=0 ){ - assert( pWInfo->eDistinct==0 ); - pWInfo->eDistinct = WHERE_DISTINCT_ORDERED; + } + if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){ + pWInfo->revMask = (Bitmask)(-1); + } + if( pParse->nErr || NEVER(db->mallocFailed) ){ + goto whereBeginError; + } +#ifdef WHERETRACE_ENABLED /* !=0 */ + if( sqlite3WhereTrace ){ + int ii; + sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut); + if( pWInfo->nOBSat>0 ){ + sqlite3DebugPrintf(" ORDERBY=%d,0x%llx", pWInfo->nOBSat, pWInfo->revMask); } - andFlags &= bestPlan.plan.wsFlags; - pLevel->plan = bestPlan.plan; - pLevel->iTabCur = pTabList->a[bestJ].iCursor; - testcase( bestPlan.plan.wsFlags & WHERE_INDEXED ); - testcase( bestPlan.plan.wsFlags & WHERE_TEMP_INDEX ); - if( bestPlan.plan.wsFlags & (WHERE_INDEXED|WHERE_TEMP_INDEX) ){ - if( (wctrlFlags & WHERE_ONETABLE_ONLY) - && (bestPlan.plan.wsFlags & WHERE_TEMP_INDEX)==0 - ){ - pLevel->iIdxCur = iIdxCur; - }else{ - pLevel->iIdxCur = pParse->nTab++; + switch( pWInfo->eDistinct ){ + case WHERE_DISTINCT_UNIQUE: { + sqlite3DebugPrintf(" DISTINCT=unique"); + break; + } + case WHERE_DISTINCT_ORDERED: { + sqlite3DebugPrintf(" DISTINCT=ordered"); + break; + } + case WHERE_DISTINCT_UNORDERED: { + sqlite3DebugPrintf(" DISTINCT=unordered"); + break; } - }else{ - pLevel->iIdxCur = -1; } - sWBI.notValid &= ~getMask(pMaskSet, pTabList->a[bestJ].iCursor); - pLevel->iFrom = (u8)bestJ; - if( bestPlan.plan.nRow>=(double)1 ){ - pParse->nQueryLoop *= bestPlan.plan.nRow; + sqlite3DebugPrintf("\n"); + for(ii=0; ii<pWInfo->nLevel; ii++){ + whereLoopPrint(pWInfo->a[ii].pWLoop, sWLB.pWC); } - - /* Check that if the table scanned by this loop iteration had an - ** INDEXED BY clause attached to it, that the named index is being - ** used for the scan. If not, then query compilation has failed. - ** Return an error. - */ - pIdx = pTabList->a[bestJ].pIndex; - if( pIdx ){ - if( (bestPlan.plan.wsFlags & WHERE_INDEXED)==0 ){ - sqlite3ErrorMsg(pParse, "cannot use index: %s", pIdx->zName); - goto whereBeginError; - }else{ - /* If an INDEXED BY clause is used, the bestIndex() function is - ** guaranteed to find the index specified in the INDEXED BY clause - ** if it find an index at all. */ - assert( bestPlan.plan.u.pIdx==pIdx ); + } +#endif + /* Attempt to omit tables from the join that do not effect the result */ + if( pWInfo->nLevel>=2 + && pResultSet!=0 + && OptimizationEnabled(db, SQLITE_OmitNoopJoin) + ){ + Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet); + if( sWLB.pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, sWLB.pOrderBy); + while( pWInfo->nLevel>=2 ){ + WhereTerm *pTerm, *pEnd; + pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop; + if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break; + if( (wctrlFlags & WHERE_WANT_DISTINCT)==0 + && (pLoop->wsFlags & WHERE_ONEROW)==0 + ){ + break; } + if( (tabUsed & pLoop->maskSelf)!=0 ) break; + pEnd = sWLB.pWC->a + sWLB.pWC->nTerm; + for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){ + if( (pTerm->prereqAll & pLoop->maskSelf)!=0 + && !ExprHasProperty(pTerm->pExpr, EP_FromJoin) + ){ + break; + } + } + if( pTerm<pEnd ) break; + WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId)); + pWInfo->nLevel--; + nTabList--; } } - WHERETRACE(("*** Optimizer Finished ***\n")); - if( pParse->nErr || db->mallocFailed ){ - goto whereBeginError; - } - if( nTabList ){ - pLevel--; - pWInfo->nOBSat = pLevel->plan.nOBSat; - }else{ - pWInfo->nOBSat = 0; - } - - /* If the total query only selects a single row, then the ORDER BY - ** clause is irrelevant. - */ - if( (andFlags & WHERE_UNIQUE)!=0 && pOrderBy ){ - assert( nTabList==0 || (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ); - pWInfo->nOBSat = pOrderBy->nExpr; - } + WHERETRACE(0xffff,("*** Optimizer Finished ***\n")); + pWInfo->pParse->nQueryLoop += pWInfo->nRowOut; /* If the caller is an UPDATE or DELETE statement that is requesting ** to use a one-pass algorithm, determine if this is appropriate. - ** The one-pass algorithm only works if the WHERE clause constraints + ** The one-pass algorithm only works if the WHERE clause constrains ** the statement to update a single row. */ assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 ); - if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){ + if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 + && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){ pWInfo->okOnePass = 1; - pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY; + if( HasRowid(pTabList->a[0].pTab) ){ + pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY; + } } /* Open all tables in the pTabList and any indices selected for ** searching those tables. */ - sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */ notReady = ~(Bitmask)0; - pWInfo->nRowOut = (double)1; for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){ Table *pTab; /* Table to open */ int iDb; /* Index of database containing table/index */ @@ -5484,13 +6256,13 @@ WhereInfo *sqlite3WhereBegin( pTabItem = &pTabList->a[pLevel->iFrom]; pTab = pTabItem->pTab; - pWInfo->nRowOut *= pLevel->plan.nRow; iDb = sqlite3SchemaToIndex(db, pTab->pSchema); + pLoop = pLevel->pWLoop; if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){ /* Do nothing */ }else #ifndef SQLITE_OMIT_VIRTUALTABLE - if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){ + if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){ const char *pVTab = (const char *)sqlite3GetVTable(db, pTab); int iCur = pTabItem->iCursor; sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB); @@ -5498,13 +6270,18 @@ WhereInfo *sqlite3WhereBegin( /* noop */ }else #endif - if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 + if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){ - int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead; + int op = OP_OpenRead; + if( pWInfo->okOnePass ){ + op = OP_OpenWrite; + pWInfo->aiCurOnePass[0] = pTabItem->iCursor; + }; sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op); - testcase( pTab->nCol==BMS-1 ); - testcase( pTab->nCol==BMS ); - if( !pWInfo->okOnePass && pTab->nCol<BMS ){ + assert( pTabItem->iCursor==pLevel->iTabCur ); + testcase( !pWInfo->okOnePass && pTab->nCol==BMS-1 ); + testcase( !pWInfo->okOnePass && pTab->nCol==BMS ); + if( !pWInfo->okOnePass && pTab->nCol<BMS && HasRowid(pTab) ){ Bitmask b = pTabItem->colUsed; int n = 0; for(; b; b=b>>1, n++){} @@ -5515,23 +6292,46 @@ WhereInfo *sqlite3WhereBegin( }else{ sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); } -#ifndef SQLITE_OMIT_AUTOMATIC_INDEX - if( (pLevel->plan.wsFlags & WHERE_TEMP_INDEX)!=0 ){ - constructAutomaticIndex(pParse, sWBI.pWC, pTabItem, notReady, pLevel); - }else -#endif - if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){ - Index *pIx = pLevel->plan.u.pIdx; - KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx); - int iIndexCur = pLevel->iIdxCur; + if( pLoop->wsFlags & WHERE_INDEXED ){ + Index *pIx = pLoop->u.btree.pIndex; + int iIndexCur; + int op = OP_OpenRead; + /* iIdxCur is always set if to a positive value if ONEPASS is possible */ + assert( iIdxCur!=0 || (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 ); + if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIx) + && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0 + ){ + /* This is one term of an OR-optimization using the PRIMARY KEY of a + ** WITHOUT ROWID table. No need for a separate index */ + iIndexCur = pLevel->iTabCur; + op = 0; + }else if( pWInfo->okOnePass ){ + Index *pJ = pTabItem->pTab->pIndex; + iIndexCur = iIdxCur; + assert( wctrlFlags & WHERE_ONEPASS_DESIRED ); + while( ALWAYS(pJ) && pJ!=pIx ){ + iIndexCur++; + pJ = pJ->pNext; + } + op = OP_OpenWrite; + pWInfo->aiCurOnePass[1] = iIndexCur; + }else if( iIdxCur && (wctrlFlags & WHERE_ONETABLE_ONLY)!=0 ){ + iIndexCur = iIdxCur; + if( wctrlFlags & WHERE_REOPEN_IDX ) op = OP_ReopenIdx; + }else{ + iIndexCur = pParse->nTab++; + } + pLevel->iIdxCur = iIndexCur; assert( pIx->pSchema==pTab->pSchema ); assert( iIndexCur>=0 ); - sqlite3VdbeAddOp4(v, OP_OpenRead, iIndexCur, pIx->tnum, iDb, - (char*)pKey, P4_KEYINFO_HANDOFF); - VdbeComment((v, "%s", pIx->zName)); + if( op ){ + sqlite3VdbeAddOp3(v, op, iIndexCur, pIx->tnum, iDb); + sqlite3VdbeSetP4KeyInfo(pParse, pIx); + VdbeComment((v, "%s", pIx->zName)); + } } - sqlite3CodeVerifySchema(pParse, iDb); - notReady &= ~getMask(sWBI.pWC->pMaskSet, pTabItem->iCursor); + if( iDb>=0 ) sqlite3CodeVerifySchema(pParse, iDb); + notReady &= ~getMask(&pWInfo->sMaskSet, pTabItem->iCursor); } pWInfo->iTop = sqlite3VdbeCurrentAddr(v); if( db->mallocFailed ) goto whereBeginError; @@ -5543,67 +6343,21 @@ WhereInfo *sqlite3WhereBegin( notReady = ~(Bitmask)0; for(ii=0; ii<nTabList; ii++){ pLevel = &pWInfo->a[ii]; +#ifndef SQLITE_OMIT_AUTOMATIC_INDEX + if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){ + constructAutomaticIndex(pParse, &pWInfo->sWC, + &pTabList->a[pLevel->iFrom], notReady, pLevel); + if( db->mallocFailed ) goto whereBeginError; + } +#endif explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags); - notReady = codeOneLoopStart(pWInfo, ii, wctrlFlags, notReady); + pLevel->addrBody = sqlite3VdbeCurrentAddr(v); + notReady = codeOneLoopStart(pWInfo, ii, notReady); pWInfo->iContinue = pLevel->addrCont; } -#ifdef SQLITE_TEST /* For testing and debugging use only */ - /* Record in the query plan information about the current table - ** and the index used to access it (if any). If the table itself - ** is not used, its name is just '{}'. If no index is used - ** the index is listed as "{}". If the primary key is used the - ** index name is '*'. - */ - for(ii=0; ii<nTabList; ii++){ - char *z; - int n; - int w; - struct SrcList_item *pTabItem; - - pLevel = &pWInfo->a[ii]; - w = pLevel->plan.wsFlags; - pTabItem = &pTabList->a[pLevel->iFrom]; - z = pTabItem->zAlias; - if( z==0 ) z = pTabItem->pTab->zName; - n = sqlite3Strlen30(z); - if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){ - if( (w & WHERE_IDX_ONLY)!=0 && (w & WHERE_COVER_SCAN)==0 ){ - memcpy(&sqlite3_query_plan[nQPlan], "{}", 2); - nQPlan += 2; - }else{ - memcpy(&sqlite3_query_plan[nQPlan], z, n); - nQPlan += n; - } - sqlite3_query_plan[nQPlan++] = ' '; - } - testcase( w & WHERE_ROWID_EQ ); - testcase( w & WHERE_ROWID_RANGE ); - if( w & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){ - memcpy(&sqlite3_query_plan[nQPlan], "* ", 2); - nQPlan += 2; - }else if( (w & WHERE_INDEXED)!=0 && (w & WHERE_COVER_SCAN)==0 ){ - n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName); - if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){ - memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n); - nQPlan += n; - sqlite3_query_plan[nQPlan++] = ' '; - } - }else{ - memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3); - nQPlan += 3; - } - } - while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){ - sqlite3_query_plan[--nQPlan] = 0; - } - sqlite3_query_plan[nQPlan] = 0; - nQPlan = 0; -#endif /* SQLITE_TEST // Testing and debugging use only */ - - /* Record the continuation address in the WhereInfo structure. Then - ** clean up and return. - */ + /* Done. */ + VdbeModuleComment((v, "Begin WHERE-core")); return pWInfo; /* Jump here if malloc fails */ @@ -5624,40 +6378,56 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ Vdbe *v = pParse->pVdbe; int i; WhereLevel *pLevel; + WhereLoop *pLoop; SrcList *pTabList = pWInfo->pTabList; sqlite3 *db = pParse->db; /* Generate loop termination code. */ + VdbeModuleComment((v, "End WHERE-core")); sqlite3ExprCacheClear(pParse); for(i=pWInfo->nLevel-1; i>=0; i--){ + int addr; pLevel = &pWInfo->a[i]; + pLoop = pLevel->pWLoop; sqlite3VdbeResolveLabel(v, pLevel->addrCont); if( pLevel->op!=OP_Noop ){ - sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2); + sqlite3VdbeAddOp3(v, pLevel->op, pLevel->p1, pLevel->p2, pLevel->p3); sqlite3VdbeChangeP5(v, pLevel->p5); + VdbeCoverage(v); + VdbeCoverageIf(v, pLevel->op==OP_Next); + VdbeCoverageIf(v, pLevel->op==OP_Prev); + VdbeCoverageIf(v, pLevel->op==OP_VNext); } - if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){ + if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){ struct InLoop *pIn; int j; sqlite3VdbeResolveLabel(v, pLevel->addrNxt); for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){ sqlite3VdbeJumpHere(v, pIn->addrInTop+1); sqlite3VdbeAddOp2(v, pIn->eEndLoopOp, pIn->iCur, pIn->addrInTop); + VdbeCoverage(v); + VdbeCoverageIf(v, pIn->eEndLoopOp==OP_PrevIfOpen); + VdbeCoverageIf(v, pIn->eEndLoopOp==OP_NextIfOpen); sqlite3VdbeJumpHere(v, pIn->addrInTop-1); } sqlite3DbFree(db, pLevel->u.in.aInLoop); } sqlite3VdbeResolveLabel(v, pLevel->addrBrk); + if( pLevel->addrSkip ){ + sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrSkip); + VdbeComment((v, "next skip-scan on %s", pLoop->u.btree.pIndex->zName)); + sqlite3VdbeJumpHere(v, pLevel->addrSkip); + sqlite3VdbeJumpHere(v, pLevel->addrSkip-2); + } if( pLevel->iLeftJoin ){ - int addr; - addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); - assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 - || (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ); - if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){ + addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v); + assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 + || (pLoop->wsFlags & WHERE_INDEXED)!=0 ); + if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){ sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor); } - if( pLevel->iIdxCur>=0 ){ + if( pLoop->wsFlags & WHERE_INDEXED ){ sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur); } if( pLevel->op==OP_Return ){ @@ -5667,6 +6437,8 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ } sqlite3VdbeJumpHere(v, addr); } + VdbeModuleComment((v, "End WHERE-loop%d: %s", i, + pWInfo->pTabList->a[pLevel->iFrom].pTab->zName)); } /* The "break" point is here, just past the end of the outer loop. @@ -5674,33 +6446,65 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ */ sqlite3VdbeResolveLabel(v, pWInfo->iBreak); - /* Close all of the cursors that were opened by sqlite3WhereBegin. - */ - assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc ); + assert( pWInfo->nLevel<=pTabList->nSrc ); for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){ + int k, last; + VdbeOp *pOp; Index *pIdx = 0; struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom]; Table *pTab = pTabItem->pTab; assert( pTab!=0 ); + pLoop = pLevel->pWLoop; + + /* For a co-routine, change all OP_Column references to the table of + ** the co-routine into OP_SCopy of result contained in a register. + ** OP_Rowid becomes OP_Null. + */ + if( pTabItem->viaCoroutine && !db->mallocFailed ){ + last = sqlite3VdbeCurrentAddr(v); + k = pLevel->addrBody; + pOp = sqlite3VdbeGetOp(v, k); + for(; k<last; k++, pOp++){ + if( pOp->p1!=pLevel->iTabCur ) continue; + if( pOp->opcode==OP_Column ){ + pOp->opcode = OP_Copy; + pOp->p1 = pOp->p2 + pTabItem->regResult; + pOp->p2 = pOp->p3; + pOp->p3 = 0; + }else if( pOp->opcode==OP_Rowid ){ + pOp->opcode = OP_Null; + pOp->p1 = 0; + pOp->p3 = 0; + } + } + continue; + } + + /* Close all of the cursors that were opened by sqlite3WhereBegin. + ** Except, do not close cursors that will be reused by the OR optimization + ** (WHERE_OMIT_OPEN_CLOSE). And do not close the OP_OpenWrite cursors + ** created for the ONEPASS optimization. + */ if( (pTab->tabFlags & TF_Ephemeral)==0 && pTab->pSelect==0 && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){ - int ws = pLevel->plan.wsFlags; + int ws = pLoop->wsFlags; if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){ sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor); } - if( (ws & WHERE_INDEXED)!=0 && (ws & WHERE_TEMP_INDEX)==0 ){ + if( (ws & WHERE_INDEXED)!=0 + && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 + && pLevel->iIdxCur!=pWInfo->aiCurOnePass[1] + ){ sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur); } } - /* If this scan uses an index, make code substitutions to read data - ** from the index in preference to the table. Sometimes, this means - ** the table need never be read from. This is a performance boost, - ** as the vdbe level waits until the table is read before actually - ** seeking the table cursor to the record corresponding to the current - ** position in the index. + /* If this scan uses an index, make VDBE code substitutions to read data + ** from the index instead of from the table where possible. In some cases + ** this optimization prevents the table from ever being read, which can + ** yield a significant performance boost. ** ** Calls to the code generator in between sqlite3WhereBegin and ** sqlite3WhereEnd will have created code that references the table @@ -5708,29 +6512,30 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ ** that reference the table and converts them into opcodes that ** reference the index. */ - if( pLevel->plan.wsFlags & WHERE_INDEXED ){ - pIdx = pLevel->plan.u.pIdx; - }else if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){ + if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){ + pIdx = pLoop->u.btree.pIndex; + }else if( pLoop->wsFlags & WHERE_MULTI_OR ){ pIdx = pLevel->u.pCovidx; } - if( pIdx && !db->mallocFailed){ - int k, j, last; - VdbeOp *pOp; - - pOp = sqlite3VdbeGetOp(v, pWInfo->iTop); + if( pIdx && !db->mallocFailed ){ last = sqlite3VdbeCurrentAddr(v); - for(k=pWInfo->iTop; k<last; k++, pOp++){ + k = pLevel->addrBody; + pOp = sqlite3VdbeGetOp(v, k); + for(; k<last; k++, pOp++){ if( pOp->p1!=pLevel->iTabCur ) continue; if( pOp->opcode==OP_Column ){ - for(j=0; j<pIdx->nColumn; j++){ - if( pOp->p2==pIdx->aiColumn[j] ){ - pOp->p2 = j; - pOp->p1 = pLevel->iIdxCur; - break; - } + int x = pOp->p2; + assert( pIdx->pTable==pTab ); + if( !HasRowid(pTab) ){ + Index *pPk = sqlite3PrimaryKeyIndex(pTab); + x = pPk->aiColumn[x]; + } + x = sqlite3ColumnOfIndex(pIdx, x); + if( x>=0 ){ + pOp->p2 = x; + pOp->p1 = pLevel->iIdxCur; } - assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 - || j<pIdx->nColumn ); + assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || x>=0 ); }else if( pOp->opcode==OP_Rowid ){ pOp->p1 = pLevel->iIdxCur; pOp->opcode = OP_IdxRowid; |