From 77a94c30da6152b9cbe5383d29e2aa9661260fbe Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 5 Dec 2020 16:16:13 -0500 Subject: [PATCH] Fix missed step in removal of useless RESULT RTEs in the planner. Commit 4be058fe9 forgot that the append_rel_list would already be populated at the time we remove useless result RTEs, and it might contain PlaceHolderVars that need to be adjusted like the ones in the main parse tree. This could lead to "no relation entry for relid N" failures later on, when the planner tries to do something with an unadjusted PHV. Per report from Tom Ellis. Back-patch to v12 where the bug came in. Discussion: https://postgr.es/m/20201205173056.GF30712@cloudinit-builder --- src/backend/optimizer/prep/prepjointree.c | 1 + src/test/regress/expected/join.out | 36 +++++++++++++++++++++++ src/test/regress/sql/join.sql | 22 ++++++++++++++ 3 files changed, 59 insertions(+) diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 2b19af7cb70..722fd16eeb4 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -3090,6 +3090,7 @@ remove_result_refs(PlannerInfo *root, int varno, Node *newjtloc) subrelids = get_relids_in_jointree(newjtloc, false); Assert(!bms_is_empty(subrelids)); substitute_phv_relids((Node *) root->parse, varno, subrelids); + fix_append_rel_relids(root->append_rel_list, varno, subrelids); } /* diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out index 55f17ffe1dd..3d889314a24 100644 --- a/src/test/regress/expected/join.out +++ b/src/test/regress/expected/join.out @@ -3330,6 +3330,42 @@ select * from 1 | 2 | 2 (1 row) +-- Test proper handling of appendrel PHVs during useless-RTE removal +explain (costs off) +select * from + (select 0 as z) as t1 + left join + (select true as a) as t2 + on true, + lateral (select true as b + union all + select a as b) as t3 +where b; + QUERY PLAN +--------------------------------------- + Nested Loop + -> Result + -> Append + -> Result + -> Result + One-Time Filter: (true) +(6 rows) + +select * from + (select 0 as z) as t1 + left join + (select true as a) as t2 + on true, + lateral (select true as b + union all + select a as b) as t3 +where b; + z | a | b +---+---+--- + 0 | t | t + 0 | t | t +(2 rows) + -- -- test extraction of restriction OR clauses from join OR clause -- (we used to only do this for indexable clauses) diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql index 7a68d306d1d..9e8dfd156ab 100644 --- a/src/test/regress/sql/join.sql +++ b/src/test/regress/sql/join.sql @@ -1052,6 +1052,28 @@ select * from (select 1 as x) ss1 left join (select 2 as y) ss2 on (true), lateral (select ss2.y as z limit 1) ss3; +-- Test proper handling of appendrel PHVs during useless-RTE removal +explain (costs off) +select * from + (select 0 as z) as t1 + left join + (select true as a) as t2 + on true, + lateral (select true as b + union all + select a as b) as t3 +where b; + +select * from + (select 0 as z) as t1 + left join + (select true as a) as t2 + on true, + lateral (select true as b + union all + select a as b) as t3 +where b; + -- -- test extraction of restriction OR clauses from join OR clause -- (we used to only do this for indexable clauses)