database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-07-02 09:02:37 +03:00
Code Activity

Allow FDWs to push down quals without breaking EvalPlanQual rechecks.

Browse Source 
This fixes a long-standing bug which was discovered while investigating
the interaction between the new join pushdown code and the EvalPlanQual
machinery: if a ForeignScan appears on the inner side of a paramaterized
nestloop, an EPQ recheck would re-return the original tuple even if
it no longer satisfied the pushed-down quals due to changed parameter
values.

This fix adds a new member to ForeignScan and ForeignScanState and a
new argument to make_foreignscan, and requires changes to FDWs which
push down quals to populate that new argument with a list of quals they
have chosen to push down.  Therefore, I'm only back-patching to 9.5,
even though the bug is not new in 9.5.

Etsuro Fujita, reviewed by me and by Kyotaro Horiguchi.
This commit is contained in:
Robert Haas
2015-10-15 13:00:40 -04:00
parent 817588bc2b
commit 5fc4c26db5
13 changed files with 71 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/backend/executor/nodeForeignscan.c
View File

@ -25,6 +25,7 @@
#include "executor/executor.h"
#include "executor/nodeForeignscan.h"
#include "foreign/fdwapi.h"
#include "utils/memutils.h"
#include "utils/rel.h"
static TupleTableSlot *ForeignNext(ForeignScanState *node);
@ -72,8 +73,19 @@ ForeignNext(ForeignScanState *node)
static bool
ForeignRecheck(ForeignScanState *node, TupleTableSlot *slot)
{
/* There are no access-method-specific conditions to recheck. */
return true;
ExprContext *econtext;
/*
* extract necessary information from foreign scan node
*/
econtext = node->ss.ps.ps_ExprContext;
/* Does the tuple meet the remote qual condition? */
econtext->ecxt_scantuple = slot;
ResetExprContext(econtext);
return ExecQual(node->fdw_recheck_quals, econtext, false);
}
/* ----------------------------------------------------------------
@ -135,6 +147,9 @@ ExecInitForeignScan(ForeignScan *node, EState *estate, int eflags)
scanstate->ss.ps.qual = (List *)
ExecInitExpr((Expr *) node->scan.plan.qual,
(PlanState *) scanstate);
scanstate->fdw_recheck_quals = (List *)
ExecInitExpr((Expr *) node->fdw_recheck_quals,
(PlanState *) scanstate);
/*
* tuple table initialization