From 2cbbffff05b853733ae19ca7047cfeb9a346a497 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 7 Feb 2023 11:56:43 -0500 Subject: [PATCH] Remove leftover code in deconstruct_distribute_oj_quals(). The initial "put back OJ relids" adjustment of ojscope was incorrect and unnecessary; it seems to be a leftover from when I (tgl) was trying to get this function to work at all. Richard Guo Discussion: https://postgr.es/m/CAMbWs4-L2C47ZGZPabBAi5oDZsKmsbvhYcGCy5o=gCjsaG_ZQA@mail.gmail.com --- src/backend/optimizer/plan/initsplan.c | 7 ------- src/test/regress/expected/join.out | 26 ++++++++++++++++++++++++++ src/test/regress/sql/join.sql | 15 +++++++++++++++ 3 files changed, 41 insertions(+), 7 deletions(-) diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c index 2d9aa85e59..904f710d59 100644 --- a/src/backend/optimizer/plan/initsplan.c +++ b/src/backend/optimizer/plan/initsplan.c @@ -1903,13 +1903,6 @@ deconstruct_distribute_oj_quals(PlannerInfo *root, int save_last_rinfo_serial; ListCell *lc; - /* - * Put any OJ relids that were removed from min_righthand back into - * ojscope, else distribute_qual_to_rels will complain. - */ - ojscope = bms_join(ojscope, bms_intersect(sjinfo->commute_below, - sjinfo->syn_righthand)); - /* Identify the outer joins this one commutes with */ joins_above = sjinfo->commute_above_r; joins_below = bms_intersect(sjinfo->commute_below, diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out index 07f5aad5ea..eea8978fad 100644 --- a/src/test/regress/expected/join.out +++ b/src/test/regress/expected/join.out @@ -4982,6 +4982,32 @@ select id from a where id in ( -> Seq Scan on b (5 rows) +-- check optimization with oddly-nested outer joins +explain (costs off) +select a1.id from + (a a1 left join a a2 on true) + left join + (a a3 left join a a4 on a3.id = a4.id) + on a2.id = a3.id; + QUERY PLAN +------------------------------ + Nested Loop Left Join + -> Seq Scan on a a1 + -> Materialize + -> Seq Scan on a a2 +(4 rows) + +explain (costs off) +select a1.id from + (a a1 left join a a2 on a1.id = a2.id) + left join + (a a3 left join a a4 on a3.id = a4.id) + on a2.id = a3.id; + QUERY PLAN +------------------ + Seq Scan on a a1 +(1 row) + -- check that join removal works for a left join when joining a subquery -- that is guaranteed to be unique by its GROUP BY clause explain (costs off) diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql index 7157b5cccc..9d20b88d71 100644 --- a/src/test/regress/sql/join.sql +++ b/src/test/regress/sql/join.sql @@ -1770,6 +1770,21 @@ select id from a where id in ( select b.id from b left join c on b.id = c.id ); +-- check optimization with oddly-nested outer joins +explain (costs off) +select a1.id from + (a a1 left join a a2 on true) + left join + (a a3 left join a a4 on a3.id = a4.id) + on a2.id = a3.id; + +explain (costs off) +select a1.id from + (a a1 left join a a2 on a1.id = a2.id) + left join + (a a3 left join a a4 on a3.id = a4.id) + on a2.id = a3.id; + -- check that join removal works for a left join when joining a subquery -- that is guaranteed to be unique by its GROUP BY clause explain (costs off) -- 2.30.2