From 5fc4c26db5120bd90348b6ee3101fcddfdf54800 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 15 Oct 2015 13:00:40 -0400 Subject: Allow FDWs to push down quals without breaking EvalPlanQual rechecks. 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. --- contrib/postgres_fdw/postgres_fdw.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index e4d799cecd5..1902f1f4eae 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -748,6 +748,7 @@ postgresGetForeignPlan(PlannerInfo *root, Index scan_relid = baserel->relid; List *fdw_private; List *remote_conds = NIL; + List *remote_exprs = NIL; List *local_exprs = NIL; List *params_list = NIL; List *retrieved_attrs; @@ -769,8 +770,8 @@ postgresGetForeignPlan(PlannerInfo *root, * * This code must match "extract_actual_clauses(scan_clauses, false)" * except for the additional decision about remote versus local execution. - * Note however that we only strip the RestrictInfo nodes from the - * local_exprs list, since appendWhereClause expects a list of + * Note however that we don't strip the RestrictInfo nodes from the + * remote_conds list, since appendWhereClause expects a list of * RestrictInfos. */ foreach(lc, scan_clauses) @@ -784,11 +785,17 @@ postgresGetForeignPlan(PlannerInfo *root, continue; if (list_member_ptr(fpinfo->remote_conds, rinfo)) + { remote_conds = lappend(remote_conds, rinfo); + remote_exprs = lappend(remote_exprs, rinfo->clause); + } else if (list_member_ptr(fpinfo->local_conds, rinfo)) local_exprs = lappend(local_exprs, rinfo->clause); else if (is_foreign_expr(root, baserel, rinfo->clause)) + { remote_conds = lappend(remote_conds, rinfo); + remote_exprs = lappend(remote_exprs, rinfo->clause); + } else local_exprs = lappend(local_exprs, rinfo->clause); } @@ -874,7 +881,8 @@ postgresGetForeignPlan(PlannerInfo *root, scan_relid, params_list, fdw_private, - NIL /* no custom tlist */ ); + NIL, /* no custom tlist */ + remote_exprs); } /* -- cgit v1.2.3