Skip allocating hash table in EXPLAIN-only mode.

Author: Alexey Bashtanov
Discussion: https://www.postgresql.org/message-id/36823f65-050d-ae24-aa4d-a37726998240%40imap.cc
This commit is contained in:
Heikki Linnakangas 2020-11-18 12:39:15 +02:00
parent dfab7f2f94
commit 2cccb627f1

View File

@ -3665,7 +3665,11 @@ ExecInitAgg(Agg *node, EState *estate, int eflags)
&aggstate->hash_ngroups_limit,
&aggstate->hash_planned_partitions);
find_hash_columns(aggstate);
build_hash_tables(aggstate);
/* Skip massive memory allocation if we are just doing EXPLAIN */
if (!(eflags & EXEC_FLAG_EXPLAIN_ONLY))
build_hash_tables(aggstate);
aggstate->table_filled = false;
/* Initialize this to 1, meaning nothing spilled, yet */