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Avoid creating a RESULT RTE that's marked LATERAL.

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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
This commit is contained in:
Tom Lane 2021-07-09 13:38:24 -04:00
parent d0a02bdb8c
commit d23ac62afa
3 changed files with 15 additions and 1 deletions
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5
src/backend/optimizer/prep/prepjointree.c
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@ -1808,10 +1808,13 @@ pull_up_constant_function(PlannerInfo *root, Node *jtnode,
/* /*
* Convert the RTE to be RTE_RESULT type, signifying that we don't need to * 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->rtekind = RTE_RESULT;
rte->functions = NIL; rte->functions = NIL;
rte->lateral = false;
/* /*
* We can reuse the RangeTblRef node. * We can reuse the RangeTblRef node.

8
src/test/regress/expected/join.out
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@ -3469,6 +3469,14 @@ select unique1 from tenk1, lateral f_immutable_int4(1) x where x = unique1;
Index Cond: (unique1 = 1) Index Cond: (unique1 = 1)
(2 rows) (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) explain (costs off)
select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x; select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x;
QUERY PLAN QUERY PLAN

3
src/test/regress/sql/join.sql
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@ -1113,6 +1113,9 @@ select unique1 from tenk1, f_immutable_int4(1) x where x = unique1;
explain (costs off) explain (costs off)
select unique1 from tenk1, lateral f_immutable_int4(1) x where x = unique1; 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) explain (costs off)
select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x; select unique1, x from tenk1 join f_immutable_int4(1) x on unique1 = x;