From eb229505103eb5494c33832d422584bfdee03fc6 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 28 Sep 2010 12:08:56 -0400 Subject: Fix PlaceHolderVar mechanism's interaction with outer joins. The point of a PlaceHolderVar is to allow a non-strict expression to be evaluated below an outer join, after which its value bubbles up like a Var and can be forced to NULL when the outer join's semantics require that. However, there was a serious design oversight in that, namely that we didn't ensure that there was actually a correct place in the plan tree to evaluate the placeholder :-(. It may be necessary to delay evaluation of an outer join to ensure that a placeholder that should be evaluated below the join can be evaluated there. Per recent bug report from Kirill Simonov. Back-patch to 8.4 where the PlaceHolderVar mechanism was introduced. --- src/backend/nodes/copyfuncs.c | 1 + 1 file changed, 1 insertion(+) (limited to 'src/backend/nodes/copyfuncs.c') diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c index e07aa3ead23..5bd0ef07502 100644 --- a/src/backend/nodes/copyfuncs.c +++ b/src/backend/nodes/copyfuncs.c @@ -1806,6 +1806,7 @@ _copyPlaceHolderInfo(PlaceHolderInfo *from) COPY_NODE_FIELD(ph_var); COPY_BITMAPSET_FIELD(ph_eval_at); COPY_BITMAPSET_FIELD(ph_needed); + COPY_BITMAPSET_FIELD(ph_may_need); COPY_SCALAR_FIELD(ph_width); return newnode; -- cgit v1.2.3