From 22d9ddbb35f5d316312a2220041ff17744a72330 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 14 Aug 2010 15:47:13 +0000
Subject: [PATCH] Fix planner to make a reasonable assumption about the amount
of memory space used by array_agg(), string_agg(), and similar aggregate
functions that use "internal" as their transition datatype. The previous
coding thought this took *no* extra space, since "internal" is pass-by-value;
but actually these aggregates typically consume a great deal of space. Per
bug #5608 from Itagaki Takahiro, and fix suggestion from Hitoshi Harada.
Back-patch to 8.4, where array_agg was introduced.
---
src/backend/optimizer/util/clauses.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index f6a943fcab4..dec753b3a3d 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.287 2010/03/19 22:54:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.288 2010/08/14 15:47:13 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -549,6 +549,18 @@ count_agg_clauses_walker(Node *node, AggClauseCounts *counts)
counts->transitionSpace += avgwidth + 2 * sizeof(void *);
}
+ else if (aggtranstype == INTERNALOID)
+ {
+ /*
+ * INTERNAL transition type is a special case: although INTERNAL
+ * is pass-by-value, it's almost certainly being used as a pointer
+ * to some large data structure. We assume usage of
+ * ALLOCSET_DEFAULT_INITSIZE, which is a good guess if the data is
+ * being kept in a private memory context, as is done by
+ * array_agg() for instance.
+ */
+ counts->transitionSpace += ALLOCSET_DEFAULT_INITSIZE;
+ }
/*
* Complain if the aggregate's arguments contain any aggregates;
--
GitLab