From 6d85bb1ba79c2792214df9fa17bcc8fac229c11c Mon Sep 17 00:00:00 2001 From: Tom Lane <tgl@sss.pgh.pa.us> Date: Sat, 23 Jul 2016 20:16:48 -0400 Subject: [PATCH] Correctly set up aggregate FILTER expression in partial-aggregation plans. The aggfilter expression should be removed from the parent (combining) Aggref, since it's not supposed to apply the filter, and indeed cannot because any Vars used in the filter would not be available after the lower-level aggregation step. Per report from Jeff Janes. (This has been broken since the introduction of partial aggregation, I think. The error became obvious after commit 59a3795c2, when setrefs.c began processing the parent Aggref's fields normally and thus would detect such Vars. The special-case coding previously used in setrefs.c skipped over the parent's aggfilter field without processing it. That was broken in its own way because no other setrefs.c processing got applied either; though since the executor would not execute the filter expression, only initialize it, that oversight might not have had any visible symptoms at present.) Report: <CAMkU=1xfuPf2edAe4ZGXTmJpU7jxuKukKyvNtEXwu35B7dvejg@mail.gmail.com> --- src/backend/optimizer/plan/setrefs.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 6ea46c46812..d10a98396c7 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -1752,6 +1752,10 @@ convert_combining_aggrefs(Node *node, void *context) Aggref *child_agg; Aggref *parent_agg; + /* Assert we've not chosen to partial-ize any unsupported cases */ + Assert(orig_agg->aggorder == NIL); + Assert(orig_agg->aggdistinct == NIL); + /* * Since aggregate calls can't be nested, we needn't recurse into the * arguments. But for safety, flat-copy the Aggref node itself rather @@ -1762,13 +1766,17 @@ convert_combining_aggrefs(Node *node, void *context) /* * For the parent Aggref, we want to copy all the fields of the - * original aggregate *except* the args list. Rather than explicitly - * knowing what they all are here, we can momentarily modify child_agg - * to provide a source for copyObject. + * original aggregate *except* the args list, which we'll replace + * below, and the aggfilter expression, which should be applied only + * by the child not the parent. Rather than explicitly knowing about + * all the other fields here, we can momentarily modify child_agg to + * provide a suitable source for copyObject. */ child_agg->args = NIL; + child_agg->aggfilter = NULL; parent_agg = (Aggref *) copyObject(child_agg); child_agg->args = orig_agg->args; + child_agg->aggfilter = orig_agg->aggfilter; /* * Now, set up child_agg to represent the first phase of partial -- GitLab