From 505c008ca37c4f6f2fffcde370b5d8354c4d4dc3 Mon Sep 17 00:00:00 2001 From: Alexander Korotkov Date: Thu, 6 Jun 2024 13:44:34 +0300 Subject: Restore preprocess_groupclause() 0452b461bc made optimizer explore alternative orderings of group-by pathkeys. It eliminated preprocess_groupclause(), which was intended to match items between GROUP BY and ORDER BY. Instead, get_useful_group_keys_orderings() function generates orderings of GROUP BY elements at the time of grouping paths generation. The get_useful_group_keys_orderings() function takes into account 3 orderings of GROUP BY pathkeys and clauses: original order as written in GROUP BY, matching ORDER BY clauses as much as possible, and matching the input path as much as possible. Given that even before 0452b461b, preprocess_groupclause() could change the original order of GROUP BY clauses we don't need to consider it apart from ordering matching ORDER BY clauses. This commit restores preprocess_groupclause() to provide an ordering of GROUP BY elements matching ORDER BY before generation of paths. The new version of preprocess_groupclause() takes into account an incremental sort. The get_useful_group_keys_orderings() function now takes into 2 orderings of GROUP BY elements: the order generated preprocess_groupclause() and the order matching the input path as much as possible. Discussion: https://postgr.es/m/CAPpHfdvyWLMGwvxaf%3D7KAp-z-4mxbSH8ti2f6mNOQv5metZFzg%40mail.gmail.com Author: Alexander Korotkov Reviewed-by: Andrei Lepikhov, Pavel Borisov --- src/test/regress/expected/partition_aggregate.out | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'src/test/regress/expected/partition_aggregate.out') diff --git a/src/test/regress/expected/partition_aggregate.out b/src/test/regress/expected/partition_aggregate.out index 1b900fddf8e..5f2c0cf5786 100644 --- a/src/test/regress/expected/partition_aggregate.out +++ b/src/test/regress/expected/partition_aggregate.out @@ -901,15 +901,15 @@ SELECT a, c, sum(b), avg(c), count(*) FROM pagg_tab_m GROUP BY (a+b)/2, 2, 1 HAV Sort Key: pagg_tab_m.a, pagg_tab_m.c, (sum(pagg_tab_m.b)) -> Append -> HashAggregate - Group Key: ((pagg_tab_m.a + pagg_tab_m.b) / 2), pagg_tab_m.c, pagg_tab_m.a + Group Key: pagg_tab_m.a, pagg_tab_m.c, ((pagg_tab_m.a + pagg_tab_m.b) / 2) Filter: ((sum(pagg_tab_m.b) = 50) AND (avg(pagg_tab_m.c) > '25'::numeric)) -> Seq Scan on pagg_tab_m_p1 pagg_tab_m -> HashAggregate - Group Key: ((pagg_tab_m_1.a + pagg_tab_m_1.b) / 2), pagg_tab_m_1.c, pagg_tab_m_1.a + Group Key: pagg_tab_m_1.a, pagg_tab_m_1.c, ((pagg_tab_m_1.a + pagg_tab_m_1.b) / 2) Filter: ((sum(pagg_tab_m_1.b) = 50) AND (avg(pagg_tab_m_1.c) > '25'::numeric)) -> Seq Scan on pagg_tab_m_p2 pagg_tab_m_1 -> HashAggregate - Group Key: ((pagg_tab_m_2.a + pagg_tab_m_2.b) / 2), pagg_tab_m_2.c, pagg_tab_m_2.a + Group Key: pagg_tab_m_2.a, pagg_tab_m_2.c, ((pagg_tab_m_2.a + pagg_tab_m_2.b) / 2) Filter: ((sum(pagg_tab_m_2.b) = 50) AND (avg(pagg_tab_m_2.c) > '25'::numeric)) -> Seq Scan on pagg_tab_m_p3 pagg_tab_m_2 (15 rows) -- cgit v1.2.3