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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-03 05:16:44 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-06-03 05:16:44 +0000
commit62a67b10ff9f9eea6a4695649fb8252d2a4bc74d (patch)
tree7b54cadc082d323cda5fd24248e85b7d2ea664a3 /src/wherecode.c
parentAdding debian version 3.45.3-1. (diff)
downloadsqlite3-62a67b10ff9f9eea6a4695649fb8252d2a4bc74d.tar.xz
sqlite3-62a67b10ff9f9eea6a4695649fb8252d2a4bc74d.zip
Merging upstream version 3.46.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--src/wherecode.c42
1 files changed, 40 insertions, 2 deletions
diff --git a/src/wherecode.c b/src/wherecode.c
index 47ce36c..a620a5a 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -1338,6 +1338,27 @@ static SQLITE_NOINLINE void filterPullDown(
}
/*
+** Loop pLoop is a WHERE_INDEXED level that uses at least one IN(...)
+** operator. Return true if level pLoop is guaranteed to visit only one
+** row for each key generated for the index.
+*/
+static int whereLoopIsOneRow(WhereLoop *pLoop){
+ if( pLoop->u.btree.pIndex->onError
+ && pLoop->nSkip==0
+ && pLoop->u.btree.nEq==pLoop->u.btree.pIndex->nKeyCol
+ ){
+ int ii;
+ for(ii=0; ii<pLoop->u.btree.nEq; ii++){
+ if( pLoop->aLTerm[ii]->eOperator & (WO_IS|WO_ISNULL) ){
+ return 0;
+ }
+ }
+ return 1;
+ }
+ return 0;
+}
+
+/*
** Generate code for the start of the iLevel-th loop in the WHERE clause
** implementation described by pWInfo.
*/
@@ -1415,7 +1436,7 @@ Bitmask sqlite3WhereCodeOneLoopStart(
if( pLevel->iFrom>0 && (pTabItem[0].fg.jointype & JT_LEFT)!=0 ){
pLevel->iLeftJoin = ++pParse->nMem;
sqlite3VdbeAddOp2(v, OP_Integer, 0, pLevel->iLeftJoin);
- VdbeComment((v, "init LEFT JOIN no-match flag"));
+ VdbeComment((v, "init LEFT JOIN match flag"));
}
/* Compute a safe address to jump to if we discover that the table for
@@ -2084,7 +2105,9 @@ Bitmask sqlite3WhereCodeOneLoopStart(
}
/* Record the instruction used to terminate the loop. */
- if( pLoop->wsFlags & WHERE_ONEROW ){
+ if( (pLoop->wsFlags & WHERE_ONEROW)
+ || (pLevel->u.in.nIn && regBignull==0 && whereLoopIsOneRow(pLoop))
+ ){
pLevel->op = OP_Noop;
}else if( bRev ){
pLevel->op = OP_Prev;
@@ -2474,6 +2497,12 @@ Bitmask sqlite3WhereCodeOneLoopStart(
** iLoop==3: Code all remaining expressions.
**
** An effort is made to skip unnecessary iterations of the loop.
+ **
+ ** This optimization of causing simple query restrictions to occur before
+ ** more complex one is call the "push-down" optimization in MySQL. Here
+ ** in SQLite, the name is "MySQL push-down", since there is also another
+ ** totally unrelated optimization called "WHERE-clause push-down".
+ ** Sometimes the qualifier is omitted, resulting in an ambiguity, so beware.
*/
iLoop = (pIdx ? 1 : 2);
do{
@@ -2724,7 +2753,16 @@ SQLITE_NOINLINE void sqlite3WhereRightJoinLoop(
pRJ->regReturn);
for(k=0; k<iLevel; k++){
int iIdxCur;
+ SrcItem *pRight;
+ assert( pWInfo->a[k].pWLoop->iTab == pWInfo->a[k].iFrom );
+ pRight = &pWInfo->pTabList->a[pWInfo->a[k].iFrom];
mAll |= pWInfo->a[k].pWLoop->maskSelf;
+ if( pRight->fg.viaCoroutine ){
+ sqlite3VdbeAddOp3(
+ v, OP_Null, 0, pRight->regResult,
+ pRight->regResult + pRight->pSelect->pEList->nExpr-1
+ );
+ }
sqlite3VdbeAddOp1(v, OP_NullRow, pWInfo->a[k].iTabCur);
iIdxCur = pWInfo->a[k].iIdxCur;
if( iIdxCur ){