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Overview
| Comment: | Performance improvement to sqlite3WhereExprUsage(). |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: | fd0934139076848f2f2edfd3d74d5460 |
| User & Date: | drh 2018-06-09 02:49:11 |
Context
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2018-06-09
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| 14:13 | Improved comments an presentation for the recent IN operator decision improvement. check-in: 31e480f6 user: drh tags: trunk | |
| 02:49 | Performance improvement to sqlite3WhereExprUsage(). check-in: fd093413 user: drh tags: trunk | |
| 01:12 | Compute the bitmask of indexed columns for each index once when the Index objecct is constructed, instead of recomputing it every time it is needed. check-in: d735872e user: drh tags: trunk | |
Changes
Changes to src/whereInt.h.
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); /* whereexpr.c: */ void sqlite3WhereClauseInit(WhereClause*,WhereInfo*); void sqlite3WhereClauseClear(WhereClause*); void sqlite3WhereSplit(WhereClause*,Expr*,u8); Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*); Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*); void sqlite3WhereExprAnalyze(SrcList*, WhereClause*); void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*); |
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);
/* whereexpr.c: */
void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
void sqlite3WhereClauseClear(WhereClause*);
void sqlite3WhereSplit(WhereClause*,Expr*,u8);
Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*);
Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*);
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Changes to src/whereexpr.c.
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}
}else if( op==TK_ISNULL ){
pTerm->prereqRight = 0;
}else{
pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
}
pMaskSet->bVarSelect = 0;
prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr);
if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT;
if( ExprHasProperty(pExpr, EP_FromJoin) ){
Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
prereqAll |= x;
extraRight = x-1; /* ON clause terms may not be used with an index
** on left table of a LEFT JOIN. Ticket #3015 */
if( (prereqAll>>1)>=x ){
................................................................................
/*
** These routines walk (recursively) an expression tree and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
Bitmask mask;
if( p==0 ) return 0;
if( p->op==TK_COLUMN ){
return sqlite3WhereGetMask(pMaskSet, p->iTable);
}
mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0;
assert( !ExprHasProperty(p, EP_TokenOnly) );
if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft);
if( p->pRight ){
mask |= sqlite3WhereExprUsage(pMaskSet, p->pRight);
assert( p->x.pList==0 );
}else if( ExprHasProperty(p, EP_xIsSelect) ){
if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1;
mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
}else if( p->x.pList ){
mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
}
return mask;
}
Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
int i;
Bitmask mask = 0;
if( pList ){
for(i=0; i<pList->nExpr; i++){
mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
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}
}else if( op==TK_ISNULL ){
pTerm->prereqRight = 0;
}else{
pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight);
}
pMaskSet->bVarSelect = 0;
prereqAll = sqlite3WhereExprUsageNN(pMaskSet, pExpr);
if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT;
if( ExprHasProperty(pExpr, EP_FromJoin) ){
Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable);
prereqAll |= x;
extraRight = x-1; /* ON clause terms may not be used with an index
** on left table of a LEFT JOIN. Ticket #3015 */
if( (prereqAll>>1)>=x ){
................................................................................
/*
** These routines walk (recursively) an expression tree and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
Bitmask sqlite3WhereExprUsageNN(WhereMaskSet *pMaskSet, Expr *p){
Bitmask mask;
if( p->op==TK_COLUMN ){
return sqlite3WhereGetMask(pMaskSet, p->iTable);
}else if( ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){
assert( p->op!=TK_IF_NULL_ROW );
return 0;
}
mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0;
if( p->pLeft ) mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pLeft);
if( p->pRight ){
mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pRight);
assert( p->x.pList==0 );
}else if( ExprHasProperty(p, EP_xIsSelect) ){
if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1;
mask |= exprSelectUsage(pMaskSet, p->x.pSelect);
}else if( p->x.pList ){
mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList);
}
return mask;
}
Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){
return p ? sqlite3WhereExprUsageNN(pMaskSet,p) : 0;
}
Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){
int i;
Bitmask mask = 0;
if( pList ){
for(i=0; i<pList->nExpr; i++){
mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);
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