Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
| Comment: | Only run the constant propagation optimization on joins since that is the only scenario where it is useful. This saves prepare time for the common case of a simple query. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | propagate-const-opt |
| Files: | files | file ages | folders |
| SHA3-256: |
598d608359005b13fa1151c6c69f2fd1 |
| User & Date: | drh 2018-07-27 17:51:20 |
Context
|
2018-07-27
| ||
| 18:12 | Faster implementation of sqlite3IsBinary(). (check-in: be05d0db user: drh tags: propagate-const-opt) | |
| 17:51 | Only run the constant propagation optimization on joins since that is the only scenario where it is useful. This saves prepare time for the common case of a simple query. (check-in: 598d6083 user: drh tags: propagate-const-opt) | |
| 16:57 | Constant propagation is now restricted to just the WHERE clause. The mechanism is changed to take affinity and collation into account. This seems to give correct answers. But the search for constant propagation costs 4 million cycles in the speed test. (check-in: 82c67efb user: drh tags: propagate-const-opt) | |
Changes
Changes to src/expr.c.
328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 |
return pColl;
}
/*
** Return true if CollSeq is the default built-in BINARY.
*/
int sqlite3IsBinary(const CollSeq *p){
if( p==0 ) return 1;
if( sqlite3_stricmp(p->zName,"BINARY")==0 ) return 1;
return 0;
}
/*
** Generate code for a comparison operator.
*/
static int codeCompare(
Parse *pParse, /* The parsing (and code generating) context */
|
| < < |
328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 |
return pColl;
}
/*
** Return true if CollSeq is the default built-in BINARY.
*/
int sqlite3IsBinary(const CollSeq *p){
return p==0 || sqlite3StrICmp(p->zName,sqlite3StrBINARY)==0;
}
/*
** Generate code for a comparison operator.
*/
static int codeCompare(
Parse *pParse, /* The parsing (and code generating) context */
|
Changes to src/select.c.
5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 |
}
#endif
if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
return rc;
}
#endif
/* Do the constant propagation optimization */
if( OptimizationEnabled(db, SQLITE_PropagateConst)
&& propagateConstants(pParse, p)
){
#if SELECTTRACE_ENABLED
if( sqlite3SelectTrace & 0x100 ){
SELECTTRACE(0x100,pParse,p,("After constant propagation:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}else{
SELECTTRACE(0x100,pParse,p,("Constant propagation not possible\n"));
}
/* For each term in the FROM clause, do two things:
** (1) Authorized unreferenced tables
** (2) Generate code for all sub-queries
*/
for(i=0; i<pTabList->nSrc; i++){
|
| > > > > > | | |
5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 |
}
#endif
if( p->pNext==0 ) ExplainQueryPlanPop(pParse);
return rc;
}
#endif
/* Do the WHERE-clause constant propagation optimization if this is
** a join. No need to speed time on this operation for non-join queries
** as the equivalent optimization will be handled by query planner in
** sqlite3WhereBegin().
*/
if( pTabList->nSrc>1
&& OptimizationEnabled(db, SQLITE_PropagateConst)
&& propagateConstants(pParse, p)
){
#if SELECTTRACE_ENABLED
if( sqlite3SelectTrace & 0x100 ){
SELECTTRACE(0x100,pParse,p,("After constant propagation:\n"));
sqlite3TreeViewSelect(0, p, 0);
}
#endif
}else{
SELECTTRACE(0x100,pParse,p,("Constant propagation not helpful\n"));
}
/* For each term in the FROM clause, do two things:
** (1) Authorized unreferenced tables
** (2) Generate code for all sub-queries
*/
for(i=0; i<pTabList->nSrc; i++){
|
Changes to src/where.c.
3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 |
if( iCons>=0 && iCons<pIdxInfo->nConstraint ){
CollSeq *pC = 0;
int iTerm = pIdxInfo->aConstraint[iCons].iTermOffset;
Expr *pX = pHidden->pWC->a[iTerm].pExpr;
if( pX->pLeft ){
pC = sqlite3BinaryCompareCollSeq(pHidden->pParse, pX->pLeft, pX->pRight);
}
zRet = (pC ? pC->zName : "BINARY");
}
return zRet;
}
/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab. That table is guaranteed to be a virtual table.
|
| |
3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 |
if( iCons>=0 && iCons<pIdxInfo->nConstraint ){
CollSeq *pC = 0;
int iTerm = pIdxInfo->aConstraint[iCons].iTermOffset;
Expr *pX = pHidden->pWC->a[iTerm].pExpr;
if( pX->pLeft ){
pC = sqlite3BinaryCompareCollSeq(pHidden->pParse, pX->pLeft, pX->pRight);
}
zRet = (pC ? pC->zName : sqlite3StrBINARY);
}
return zRet;
}
/*
** Add all WhereLoop objects for a table of the join identified by
** pBuilder->pNew->iTab. That table is guaranteed to be a virtual table.
|
Changes to src/whereexpr.c.
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 |
** LIKE on all candidate expressions by clearing the isComplete flag
*/
if( c=='A'-1 ) isComplete = 0;
c = sqlite3UpperToLower[c];
}
*pC = c + 1;
}
zCollSeqName = noCase ? "NOCASE" : "BINARY";
pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
pStr1);
transferJoinMarkings(pNewExpr1, pExpr);
idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
testcase( idxNew1==0 );
|
| |
1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 |
** LIKE on all candidate expressions by clearing the isComplete flag
*/
if( c=='A'-1 ) isComplete = 0;
c = sqlite3UpperToLower[c];
}
*pC = c + 1;
}
zCollSeqName = noCase ? "NOCASE" : sqlite3StrBINARY;
pNewExpr1 = sqlite3ExprDup(db, pLeft, 0);
pNewExpr1 = sqlite3PExpr(pParse, TK_GE,
sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName),
pStr1);
transferJoinMarkings(pNewExpr1, pExpr);
idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags);
testcase( idxNew1==0 );
|