typedef struct WhereMaskSet WhereMaskSet;
typedef struct WhereOrInfo WhereOrInfo;
typedef struct WhereAndInfo WhereAndInfo;
-typedef struct WhereCost WhereCost;
+typedef struct WhereLevel WhereLevel;
+typedef struct WhereLoop WhereLoop;
+typedef struct WherePath WherePath;
+typedef struct WhereTerm WhereTerm;
+typedef struct WhereLoopBuilder WhereLoopBuilder;
+typedef struct WhereScan WhereScan;
+
+/*
+** Cost X is tracked as 10*log2(X) stored in a 16-bit integer. The
+** maximum cost is 64*(2**63) which becomes 6900. So all costs can be
+** be stored in a 16-bit unsigned integer without risk of overflow.
+*/
+typedef unsigned short int WhereCost;
+
+/*
+** For each nested loop in a WHERE clause implementation, the WhereInfo
+** structure contains a single instance of this structure. This structure
+** is intended to be private to the where.c module and should not be
+** access or modified by other modules.
+**
+** The pIdxInfo field is used to help pick the best index on a
+** virtual table. The pIdxInfo pointer contains indexing
+** information for the i-th table in the FROM clause before reordering.
+** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
+** All other information in the i-th WhereLevel object for the i-th table
+** after FROM clause ordering.
+*/
+struct WhereLevel {
+ int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
+ int iTabCur; /* The VDBE cursor used to access the table */
+ int iIdxCur; /* The VDBE cursor used to access pIdx */
+ int addrBrk; /* Jump here to break out of the loop */
+ int addrNxt; /* Jump here to start the next IN combination */
+ int addrCont; /* Jump here to continue with the next loop cycle */
+ int addrFirst; /* First instruction of interior of the loop */
+ u8 iFrom; /* Which entry in the FROM clause */
+ u8 op, p5; /* Opcode and P5 of the opcode that ends the loop */
+ int p1, p2; /* Operands of the opcode used to ends the loop */
- union { /* Information that depends on plan.wsFlags */
++ union { /* Information that depends on pWLoop->wsFlags */
+ struct {
+ int nIn; /* Number of entries in aInLoop[] */
+ struct InLoop {
+ int iCur; /* The VDBE cursor used by this IN operator */
+ int addrInTop; /* Top of the IN loop */
+ u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
+ } *aInLoop; /* Information about each nested IN operator */
- } in; /* Used when plan.wsFlags&WHERE_IN_ABLE */
++ } in; /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
+ Index *pCovidx; /* Possible covering index for WHERE_MULTI_OR */
+ } u;
+ struct WhereLoop *pWLoop; /* The selected WhereLoop object */
+};
+
+/*
+** Each instance of this object represents a way of evaluating one
+** term of a join. The WhereClause object holds a table of these
+** objects using (maskSelf,prereq,) as the primary key. Note that the
+** same join term might have multiple associated WhereLoop objects.
+*/
+struct WhereLoop {
+ Bitmask prereq; /* Bitmask of other loops that must run first */
+ Bitmask maskSelf; /* Bitmask identifying table iTab */
+#ifdef SQLITE_DEBUG
+ char cId; /* Symbolic ID of this loop for debugging use */
+#endif
+ u8 iTab; /* Position in FROM clause of table for this loop */
+ u8 iSortIdx; /* Sorting index number. 0==None */
+ WhereCost rSetup; /* One-time setup cost (ex: create transient index) */
+ WhereCost rRun; /* Cost of running each loop */
+ WhereCost nOut; /* Estimated number of output rows */
+ union {
+ struct { /* Information for internal btree tables */
+ int nEq; /* Number of equality constraints */
+ Index *pIndex; /* Index used, or NULL */
+ } btree;
+ struct { /* Information for virtual tables */
+ int idxNum; /* Index number */
+ u8 needFree; /* True if sqlite3_free(idxStr) is needed */
+ u8 isOrdered; /* True if satisfies ORDER BY */
+ u16 omitMask; /* Terms that may be omitted */
+ char *idxStr; /* Index identifier string */
+ } vtab;
+ } u;
+ u32 wsFlags; /* WHERE_* flags describing the plan */
+ u16 nLTerm; /* Number of entries in aLTerm[] */
+ /**** whereLoopXfer() copies fields above ***********************/
+# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
+ u16 nLSlot; /* Number of slots allocated for aLTerm[] */
+ WhereTerm **aLTerm; /* WhereTerms used */
+ WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
+ WhereTerm *aLTermSpace[4]; /* Initial aLTerm[] space */
+};
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/*
+** Each instance of this object holds a sequence of WhereLoop objects
+** that implement some or all of the entire query plan.
+*/
+struct WherePath {
+ Bitmask maskLoop; /* Bitmask of all WhereLoop objects in this path */
+ Bitmask revLoop; /* aLoop[]s that should be reversed for ORDER BY */
+ WhereCost nRow; /* Estimated number of rows generated by this path */
+ WhereCost rCost; /* Total cost of this path */
+ u8 isOrdered; /* True if this path satisfies ORDER BY */
+ u8 isOrderedValid; /* True if the isOrdered field is valid */
+ WhereLoop **aLoop; /* Array of WhereLoop objects implementing this path */
+};
/*
** The query generator uses an array of instances of this structure to
}
/*
-** 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.
+** Code an OP_Affinity opcode to apply the column affinity string zAff
+** to the n registers starting at base.
**
-** The table being queried has a cursor number of "base". pIdx is the
-** index that is postulated for use to access the table.
+** As an optimization, SQLITE_AFF_NONE entries (which are no-ops) at the
+** beginning and end of zAff are ignored. If all entries in zAff are
+** SQLITE_AFF_NONE, then no code gets generated.
**
-** 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.
+** This routine makes its own copy of zAff so that the caller is free
+** to modify zAff after this routine returns.
*/
-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;
+static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
+ Vdbe *v = pParse->pVdbe;
+ if( zAff==0 ){
+ assert( pParse->db->mallocFailed );
+ return;
}
+ assert( v!=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
+ /* Adjust base and n to skip over SQLITE_AFF_NONE entries at the beginning
+ ** and end of the affinity string.
*/
- if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat;
- *pbObUnique = uniqueNotNull;
-
- /* Return the necessary scan order back to the caller */
- *pbRev = sortOrder & 1;
+ while( n>0 && zAff[0]==SQLITE_AFF_NONE ){
+ n--;
+ base++;
+ zAff++;
+ }
+ while( n>1 && zAff[n-1]==SQLITE_AFF_NONE ){
+ n--;
+ }
- /* 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++;
- }
+ /* Code the OP_Affinity opcode if there is anything left to do. */
+ if( n>0 ){
+ sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
+ sqlite3VdbeChangeP4(v, -1, zAff, n);
+ sqlite3ExprCacheAffinityChange(pParse, base, n);
}
- 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.
+** Generate code for a single equality term of the WHERE clause. An equality
+** term can be either X=expr or X IN (...). pTerm is the term to be
+** coded.
**
-** 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.
+** The current value for the constraint is left in register iReg.
**
-** 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.
+** For a constraint of the form X=expr, the expression is evaluated and its
+** result is left on the stack. For constraints of the form X IN (...)
+** this routine sets up a loop that will iterate over all values of X.
*/
-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;
+static int codeEqualityTerm(
+ Parse *pParse, /* The parsing context */
+ 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;
+ Vdbe *v = pParse->pVdbe;
+ int iReg; /* Register holding results */
- /* 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;
+ assert( iTarget>0 );
+ if( pX->op==TK_EQ ){
+ iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
+ }else if( pX->op==TK_ISNULL ){
+ iReg = iTarget;
+ sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
+#ifndef SQLITE_OMIT_SUBQUERY
}else{
- idxEqTermMask = WO_EQ|WO_IN|WO_ISNULL;
- }
+ int eType;
+ int iTab;
+ struct InLoop *pIn;
+ WhereLoop *pLoop = pLevel->pWLoop;
- 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);
- }
-}
-
-/*
-** Disable a term in the WHERE clause. Except, do not disable the term
-** if it controls a LEFT OUTER JOIN and it did not originate in the ON
-** or USING clause of that join.
-**
-** Consider the term t2.z='ok' in the following queries:
-**
-** (1) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x WHERE t2.z='ok'
-** (2) SELECT * FROM t1 LEFT JOIN t2 ON t1.a=t2.x AND t2.z='ok'
-** (3) SELECT * FROM t1, t2 WHERE t1.a=t2.x AND t2.z='ok'
-**
-** The t2.z='ok' is disabled in the in (2) because it originates
-** 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
-** loop. We would get the correct results if nothing were ever disabled,
-** but joins might run a little slower. The trick is to disable as much
-** as we can without disabling too much. If we disabled in (1), we'd get
-** the wrong answer. See ticket #813.
-*/
-static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
- if( pTerm
- && (pTerm->wtFlags & TERM_CODED)==0
- && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
- ){
- pTerm->wtFlags |= TERM_CODED;
- if( pTerm->iParent>=0 ){
- WhereTerm *pOther = &pTerm->pWC->a[pTerm->iParent];
- if( (--pOther->nChild)==0 ){
- disableTerm(pLevel, pOther);
- }
- }
- }
-}
-
-/*
-** Code an OP_Affinity opcode to apply the column affinity string zAff
-** to the n registers starting at base.
-**
-** As an optimization, SQLITE_AFF_NONE entries (which are no-ops) at the
-** beginning and end of zAff are ignored. If all entries in zAff are
-** SQLITE_AFF_NONE, then no code gets generated.
-**
-** This routine makes its own copy of zAff so that the caller is free
-** to modify zAff after this routine returns.
-*/
-static void codeApplyAffinity(Parse *pParse, int base, int n, char *zAff){
- Vdbe *v = pParse->pVdbe;
- if( zAff==0 ){
- assert( pParse->db->mallocFailed );
- return;
- }
- assert( v!=0 );
-
- /* Adjust base and n to skip over SQLITE_AFF_NONE entries at the beginning
- ** and end of the affinity string.
- */
- while( n>0 && zAff[0]==SQLITE_AFF_NONE ){
- n--;
- base++;
- zAff++;
- }
- while( n>1 && zAff[n-1]==SQLITE_AFF_NONE ){
- n--;
- }
-
- /* Code the OP_Affinity opcode if there is anything left to do. */
- if( n>0 ){
- sqlite3VdbeAddOp2(v, OP_Affinity, base, n);
- sqlite3VdbeChangeP4(v, -1, zAff, n);
- sqlite3ExprCacheAffinityChange(pParse, base, n);
- }
-}
-
-
-/*
-** Generate code for a single equality term of the WHERE clause. An equality
-** term can be either X=expr or X IN (...). pTerm is the term to be
-** coded.
-**
-** The current value for the constraint is left in register iReg.
-**
-** For a constraint of the form X=expr, the expression is evaluated and its
-** result is left on the stack. For constraints of the form X IN (...)
-** this routine sets up a loop that will iterate over all values of X.
-*/
-static int codeEqualityTerm(
- Parse *pParse, /* The parsing context */
- 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 iTarget /* Attempt to leave results in this register */
-){
- Expr *pX = pTerm->pExpr;
- Vdbe *v = pParse->pVdbe;
- int iReg; /* Register holding results */
-
- assert( iTarget>0 );
- if( pX->op==TK_EQ ){
- iReg = sqlite3ExprCodeTarget(pParse, pX->pRight, iTarget);
- }else if( pX->op==TK_ISNULL ){
- iReg = iTarget;
- sqlite3VdbeAddOp2(v, OP_Null, 0, iReg);
-#ifndef SQLITE_OMIT_SUBQUERY
- }else{
- int eType;
- int iTab;
- struct InLoop *pIn;
- u8 bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
-
- 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;
}
** 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 ){
++ testcase( pLoop->wsFlags & WHERE_BTM_LIMIT );
++ testcase( pLoop->wsFlags & WHERE_TOP_LIMIT );
+ if( (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
}
projects / thirdparty / sqlite.git / commitdiff
