From 9807b9aedc6e8b8a497db161b3d2d9f83648ea5b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 9 Jul 2021 13:38:24 -0400 Subject: [PATCH] Avoid creating a RESULT RTE that's marked LATERAL. Commit 7266d0997 added code to pull up simple constant function results, converting the RTE_FUNCTION RTE to a dummy RTE_RESULT RTE since it no longer need be scanned. But I forgot to clear the LATERAL flag if the RTE has it set. If the function reduced to a constant, it surely contains no lateral references so this simplification is logically OK. It's needed because various other places will Assert that RESULT RTEs aren't LATERAL. Per bug #17097 from Yaoguang Chen. Back-patch to v13 where the faulty code came in. Discussion: https://postgr.es/m/17097-3372ef9f798fc94f@postgresql.org --- src/backend/optimizer/prep/prepjointree.c | 5 ++++- src/test/regress/expected/join.out | 8 ++++++++ src/test/regress/sql/join.sql | 3 +++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c index 9ff2b595a8..08a73fb9d8 100644 --- a/src/backend/optimizer/prep/prepjointree.c +++ b/src/backend/optimizer/prep/prepjointree.c @@ -1802,10 +1802,13 @@ pull_up_constant_function(PlannerInfo *root, Node *jtnode, /* * Convert the RTE to be RTE_RESULT type, signifying that we don't need to - * scan it anymore, and zero out RTE_FUNCTION-specific fields. + * scan it anymore, and zero out RTE_FUNCTION-specific fields. Also make + * sure the RTE is not marked LATERAL, since elsewhere we don't expect + * RTE_RESULTs to be LATERAL. */ rte->rtekind = RTE_RESULT; rte->functions = NIL; + rte->lateral = false; /* * We can reuse the RangeTblRef node. diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out index 37ef22f3d5..9b9fe11f27 100644 --- a/src/test/regress/expected/join.out +++ b/src/test/regress/expected/join.out @@ -3414,6 +3414,14 @@ select unique1 from tenk1, lateral f_immutable_int4(1) x where x = unique1; Index Cond: (unique1 = 1) (2 rows) +explain (costs off) +select unique1 from tenk1, lateral f_immutable_int4(1) x where x in (select 17); + QUERY PLAN +-------------------------- + Result + One-Time Filter: false +(2 rows) + explain (costs off) select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x; QUERY PLAN diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql index 8818184860..2fc4f030f7 100644 --- a/src/test/regress/sql/join.sql +++ b/src/test/regress/sql/join.sql @@ -1099,6 +1099,9 @@ select unique1 from tenk1, f_immutable_int4(1) x where x = unique1; explain (costs off) select unique1 from tenk1, lateral f_immutable_int4(1) x where x = unique1; +explain (costs off) +select unique1 from tenk1, lateral f_immutable_int4(1) x where x in (select 17); + explain (costs off) select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x;