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Performance improvement for column name lookup.

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FossilOrigin-Name: 1e4b6a93987cdfbf829e2ff35ef417c290625f2894ad11949e301af518f1fb44
This commit is contained in:
drh
2020-04-06 18:16:31 +00:00
parent 85f2c76cf9
commit d44390c8c5
8 changed files with 37 additions and 15 deletions
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7
src/resolve.c
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@@ -294,6 +294,7 @@ static int lookupName(
if( pSrcList ){
for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){
u8 hCol;
pTab = pItem->pTab;
assert( pTab!=0 && pTab->zName!=0 );
assert( pTab->nCol>0 );
@@ -327,8 +328,9 @@ static int lookupName(
if( 0==(cntTab++) ){
pMatch = pItem;
}
hCol = sqlite3StrIHash(zCol);
for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
if( pCol->hName==hCol && sqlite3StrICmp(pCol->zName, zCol)==0 ){
/* If there has been exactly one prior match and this match
** is for the right-hand table of a NATURAL JOIN or is in a
** USING clause, then skip this match.
@@ -389,10 +391,11 @@ static int lookupName(
if( pTab ){
int iCol;
u8 hCol = sqlite3StrIHash(zCol);
pSchema = pTab->pSchema;
cntTab++;
for(iCol=0, pCol=pTab->aCol; iCol<pTab->nCol; iCol++, pCol++){
if( sqlite3StrICmp(pCol->zName, zCol)==0 ){
if( pCol->hName==hCol && sqlite3StrICmp(pCol->zName, zCol)==0 ){
if( iCol==pTab->iPKey ){
iCol = -1;
}