#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 0x00800000 /* Use index only - omit table */
-#define WHERE_ORDERBY 0x01000000 /* Output will appear in correct order */
-#define WHERE_REVERSE 0x02000000 /* Scan in reverse order */
-#define WHERE_UNIQUE 0x04000000 /* Selects no more than one row */
+#define WHERE_IDX_ONLY 0x00400000 /* Use index only - omit table */
+#define WHERE_ORDERBY 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_VIRTUALTABLE 0x08000000 /* Use virtual-table processing */
#define WHERE_MULTI_OR 0x10000000 /* OR using multiple indices */
#define WHERE_TEMP_INDEX 0x20000000 /* Uses an ephemeral index */
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.
-**
-** nEqCol is the number of columns of pIdx that are used as equality
-** constraints and where the other side of the == is an ordered column
-** or constant. An "order column" in the previous sentence means a column
-** in table from an outer loop whose values will always appear in the
-** correct order due to othre index, or because the outer loop generates
-** a unique result. Any of the first nEqCol columns of pIdx may be missing
-** from the ORDER BY clause and the match can still be a success.
-**
-** 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 nEqCol, /* Number of index columns with ordered == constraints */
- int wsFlags, /* Index usages flags */
- int bOuterRev, /* True if outer loops scan in reverse order */
- int *pbRev /* Set to 1 for reverse-order scan of pIdx */
-){
- int i; /* Number of pIdx terms used */
- int j; /* Number of ORDER BY terms satisfied */
- int sortOrder = 0; /* XOR of index and ORDER BY sort direction */
- int nTerm; /* Number of ORDER BY terms */
- struct ExprList_item *pTerm; /* A term of the ORDER BY clause */
- 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 nEqOneRow; /* Idx columns that ref unique values */
-
- if( p->i==0 ){
- nPriorSat = 0;
- nEqOneRow = nEqCol;
- }else{
- if( OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
- nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
- sortOrder = bOuterRev;
- nEqOneRow = 0;
- }
- if( p->i>0 && nEqCol==0 /*&& !allOuterLoopsUnique(p)*/ ) return nPriorSat;
- pOrderBy = p->pOrderBy;
- if( !pOrderBy ) return nPriorSat;
- if( wsFlags & WHERE_COLUMN_IN ) return nPriorSat;
- if( pIdx->bUnordered ) return nPriorSat;
- nTerm = pOrderBy->nExpr;
- 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.
- */
- for(i=0,j=nPriorSat,pTerm=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){
- Expr *pExpr; /* The expression of the ORDER BY pTerm */
- CollSeq *pColl; /* The collating sequence of pExpr */
- 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 */
- const char *zColl; /* Name of the collating sequence for i-th index term */
-
- pExpr = pTerm->pExpr;
- if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
- /* Can not use an index sort on anything that is not a column in the
- ** left-most table of the FROM clause */
- break;
- }
- pColl = sqlite3ExprCollSeq(pParse, pExpr);
- if( !pColl ){
- pColl = db->pDfltColl;
- }
- 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];
- }else{
- iColumn = -1;
- iSortOrder = 0;
- zColl = pColl->zName;
- }
- if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
- /* Term j of the ORDER BY clause does not match column i of the index */
- if( i<nEqCol ){
- /* If an index column that is constrained by == fails to match an
- ** ORDER BY term, that is OK. Just ignore that column of the index
- */
- continue;
- }else if( i==pIdx->nColumn ){
- /* Index column i is the rowid. All other terms match. */
- break;
- }else{
- /* If an index column fails to match and is not constrained by ==
- ** then the index cannot satisfy the ORDER BY constraint.
- */
- return nPriorSat;
- }
- }
- assert( pIdx->aSortOrder!=0 || iColumn==-1 );
- assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
- assert( iSortOrder==0 || iSortOrder==1 );
- termSortOrder = iSortOrder ^ pTerm->sortOrder;
- if( i>nEqOneRow ){
- if( termSortOrder!=sortOrder ){
- /* Indices can only be used if all ORDER BY terms past the
- ** equality constraints are all either DESC or ASC. */
- break;
- }
- }else{
- sortOrder = termSortOrder;
- }
- j++;
- pTerm++;
- if( iColumn<0 ){
- seenRowid = 1;
- break;
- }
- }
- *pbRev = sortOrder;
-
- /* 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( seenRowid ||
- ( (wsFlags & WHERE_COLUMN_NULL)==0
- && i>=pIdx->nColumn
- && indexIsUniqueNotNull(pIdx, nEqCol)
- )
- ){
- /* 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;
-}
-
/*
** Prepare a crude estimate of the logarithm of the input value.
** The results need not be exact. This is only used for estimating
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;
+ }
if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
pIdx = pLevel->plan.u.pIdx;
if( iCol<0 ){
assert( pExpr->op==TK_EQ );
assert( pExpr->pLeft!=0 && pExpr->pLeft->op==TK_COLUMN );
assert( pExpr->pRight!=0 );
- if( p->i==0 ){
- return 1; /* All == are ordered in the outer loop */
- }
if( pTerm->prereqRight==0 ){
return 1; /* RHS of the == is a constant */
}
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.
+**
+** nEqCol is the number of columns of pIdx that are used as equality
+** constraints and where the other side of the == is an ordered column
+** or constant. An "order column" in the previous sentence means a column
+** in table from an outer loop whose values will always appear in the
+** correct order due to othre index, or because the outer loop generates
+** a unique result. Any of the first nEqCol columns of pIdx may be missing
+** from the ORDER BY clause and the match can still be a success.
+**
+** 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 nEqCol, /* Number of index columns with ordered == constraints */
+ int wsFlags, /* Index usages flags */
+ int bOuterRev, /* True if outer loops scan in reverse order */
+ int *pbRev /* Set to 1 for reverse-order scan of pIdx */
+){
+ int i; /* Number of pIdx terms used */
+ int j; /* Number of ORDER BY terms satisfied */
+ int sortOrder = 0; /* XOR of index and ORDER BY sort direction */
+ int nTerm; /* Number of ORDER BY terms */
+ struct ExprList_item *pTerm; /* A term of the ORDER BY clause */
+ 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 nEqOneRow; /* Idx columns that ref unique values */
+
+ if( p->i==0 ){
+ nPriorSat = 0;
+ }else{
+ nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
+ if( OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return nPriorSat;
+ }
+ if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
+ nEqOneRow = nEqCol;
+ }else{
+ if( nEqCol==0 ) return nPriorSat;
+ sortOrder = bOuterRev;
+ nEqOneRow = 0;
+ }
+ pOrderBy = p->pOrderBy;
+ assert( pOrderBy!=0 );
+ if( wsFlags & WHERE_COLUMN_IN ) return nPriorSat;
+ if( pIdx->bUnordered ) return nPriorSat;
+ nTerm = pOrderBy->nExpr;
+ 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.
+ */
+ for(i=0,j=nPriorSat,pTerm=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){
+ Expr *pExpr; /* The expression of the ORDER BY pTerm */
+ CollSeq *pColl; /* The collating sequence of pExpr */
+ 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 */
+ const char *zColl; /* Name of the collating sequence for i-th index term */
+
+ pExpr = pTerm->pExpr;
+ if( pExpr->op!=TK_COLUMN || pExpr->iTable!=base ){
+ /* Can not use an index sort on anything that is not a column in the
+ ** left-most table of the FROM clause */
+ break;
+ }
+ pColl = sqlite3ExprCollSeq(pParse, pExpr);
+ if( !pColl ){
+ pColl = db->pDfltColl;
+ }
+ 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];
+ }else{
+ iColumn = -1;
+ iSortOrder = 0;
+ zColl = pColl->zName;
+ }
+ if( pExpr->iColumn!=iColumn || sqlite3StrICmp(pColl->zName, zColl) ){
+ /* Term j of the ORDER BY clause does not match column i of the index */
+ if( i<nEqCol ){
+ /* If an index column that is constrained by == fails to match an
+ ** ORDER BY term, that is OK. Just ignore that column of the index
+ */
+ continue;
+ }else if( i==pIdx->nColumn ){
+ /* Index column i is the rowid. All other terms match. */
+ break;
+ }else{
+ /* If an index column fails to match and is not constrained by ==
+ ** then the index cannot satisfy the ORDER BY constraint.
+ */
+ return nPriorSat;
+ }
+ }
+ assert( pIdx->aSortOrder!=0 || iColumn==-1 );
+ assert( pTerm->sortOrder==0 || pTerm->sortOrder==1 );
+ assert( iSortOrder==0 || iSortOrder==1 );
+ termSortOrder = iSortOrder ^ pTerm->sortOrder;
+ if( i>nEqOneRow ){
+ if( termSortOrder!=sortOrder ){
+ /* Indices can only be used if all ORDER BY terms past the
+ ** equality constraints are all either DESC or ASC. */
+ break;
+ }
+ }else{
+ sortOrder = termSortOrder;
+ }
+ j++;
+ pTerm++;
+ if( iColumn<0 ){
+ seenRowid = 1;
+ break;
+ }
+ }
+ *pbRev = sortOrder;
+
+ /* 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( seenRowid ||
+ ( (wsFlags & WHERE_COLUMN_NULL)==0
+ && i>=pIdx->nColumn
+ && indexIsUniqueNotNull(pIdx, nEqCol)
+ )
+ ){
+ /* 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
testcase( wsFlags & WHERE_COLUMN_NULL );
if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
wsFlags |= WHERE_UNIQUE;
+ if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
+ wsFlags |= WHERE_ALL_UNIQUE;
+ }
}
}else if( pProbe->bUnordered==0 ){
int j = (nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[nEq]);
projects / thirdparty / sqlite.git / commitdiff
