database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-11 01:42:22 +03:00
Code Activity

Remove the push-down optimization restriction that was added by

Browse Source 
check-in [1ad41840c5e0fa70] because it is no longer needed after
the enhancements to compound query processing in check-in [27655c9353620aa5]
This resolves the performance regression reported by
[forum:/forumpost/bcc4375032|forum post bcc4375032].

FossilOrigin-Name: aa6bd6dff751223e302575c60f335707e4bb820bff716cab3706b564e18ed7ed
This commit is contained in:
drh
2023-02-22 20:42:15 +00:00
parent dbb3260627
commit bcb3215630
4 changed files with 51 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
src/select.c
View File

@@ -4238,8 +4238,7 @@ static int compoundHasDifferentAffinities(Select *p){
** query or there are no RIGHT or FULL JOINs in any arm
** of the subquery. (This is a duplicate of condition (27b).)
** (17h) The corresponding result set expressions in all arms of the
** compound must have the same affinity. (See restriction (9)
** on the push-down optimization.)
** compound must have the same affinity.
**
** The parent and sub-query may contain WHERE clauses. Subject to
** rules (11), (13) and (14), they may also contain ORDER BY,
@@ -5107,10 +5106,6 @@ static int pushDownWindowCheck(Parse *pParse, Select *pSubq, Expr *pExpr){
** or EXCEPT, then all of the result set columns for all arms of
** the compound must use the BINARY collating sequence.
**
** (9) If the subquery is a compound, then all arms of the compound must
** have the same affinity. (This is the same as restriction (17h)
** for query flattening.)
**
**
** Return 0 if no changes are made and non-zero if one or more WHERE clause
** terms are duplicated into the subquery.
@@ -5141,9 +5136,6 @@ static int pushDownWhereTerms(
if( pSel->pWin ) return 0; /* restriction (6b) */
#endif
}
if( compoundHasDifferentAffinities(pSubq) ){
return 0; /* restriction (9) */
}
if( notUnionAll ){
/* If any of the compound arms are connected using UNION, INTERSECT,
** or EXCEPT, then we must ensure that none of the columns use a