postgres.git / summary / log / commit / refs

commit    1d98fdaed89c00465ef68fa2804967ea27b03abc
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Fri Jul 09 17:38:24 2021 +0000

    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 62a16687963..b164866c729 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -1801,10 +1801,13 @@ 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 fec0325e73e..19cd0569876 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -3469,6 +3469,14 @@ 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 7f866c603b8..2a0e2d12d83 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1113,6 +1113,9 @@ 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;
 


[parent: 5620ec83362d]