Ensure dummy paths have correct required_outer if rel is parameterized.

The assertions added by commits 34ea1ab7f et al found another problem:
set_dummy_rel_pathlist and mark_dummy_rel were failing to label
the dummy paths they create with the correct outer_relids, in case
the relation is necessarily parameterized due to having lateral
references in its tlist.  It's likely that this has no user-visible
consequences in production builds, at the moment; but still an assertion
failure is a bad thing, so back-patch the fix.

Per bug #15694 from Roman Zharkov (via Alexander Lakhin)
and an independent report by Tushar Ahuja.

Discussion: https://postgr.es/m/15694-74f2ca97e7044f7f@postgresql.org
Discussion: https://postgr.es/m/7d72ab20-c725-3ce2-f99d-4e64dd8a0de6@enterprisedb.com

diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index e376c49265c0368232f164615ebe107609423e49..2154717e0491ee0325a99a4194cf256390bdca67 100644 (file)
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -1768,7 +1768,9 @@ set_dummy_rel_pathlist(RelOptInfo *rel)
    rel->partial_pathlist = NIL;
 
    /* Set up the dummy path */
-   add_path(rel, (Path *) create_append_path(rel, NIL, NULL, 0, NIL));
+   add_path(rel, (Path *) create_append_path(rel, NIL,
+                                             rel->lateral_relids,
+                                             0, NIL));
 
    /*
     * We set the cheapest-path fields immediately, just in case they were

diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c
index ae3c487e08a6d5f5786298479d2f555f92d9b0ec..e16855924c995c680c78b8b6d17e973a549e0f10 100644 (file)
--- a/src/backend/optimizer/path/joinrels.c
+++ b/src/backend/optimizer/path/joinrels.c
@@ -1245,7 +1245,9 @@ mark_dummy_rel(RelOptInfo *rel)
    rel->partial_pathlist = NIL;
 
    /* Set up the dummy path */
-   add_path(rel, (Path *) create_append_path(rel, NIL, NULL, 0, NIL));
+   add_path(rel, (Path *) create_append_path(rel, NIL,
+                                             rel->lateral_relids,
+                                             0, NIL));
 
    /* Set or update cheapest_total_path and related fields */
    set_cheapest(rel);

diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 9097c4a97ca270d3e0af45a30f1ea427707fabe6..e7a890a907db743b50dce283bb40e24a1e779bbb 100644 (file)
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -5291,6 +5291,35 @@ select * from
          Output: 3
 (11 rows)
 
+-- check dummy rels with lateral references (bug #15694)
+explain (verbose, costs off)
+select * from int8_tbl i8 left join lateral
+  (select *, i8.q2 from int4_tbl where false) ss on true;
+              QUERY PLAN              
+--------------------------------------
+ Nested Loop Left Join
+   Output: i8.q1, i8.q2, f1, (i8.q2)
+   ->  Seq Scan on public.int8_tbl i8
+         Output: i8.q1, i8.q2
+   ->  Result
+         Output: f1, i8.q2
+         One-Time Filter: false
+(7 rows)
+
+explain (verbose, costs off)
+select * from int8_tbl i8 left join lateral
+  (select *, i8.q2 from int4_tbl i1, int4_tbl i2 where false) ss on true;
+               QUERY PLAN                
+-----------------------------------------
+ Nested Loop Left Join
+   Output: i8.q1, i8.q2, f1, f1, (i8.q2)
+   ->  Seq Scan on public.int8_tbl i8
+         Output: i8.q1, i8.q2
+   ->  Result
+         Output: f1, f1, i8.q2
+         One-Time Filter: false
+(7 rows)
+
 -- check handling of nested appendrels inside LATERAL
 select * from
   ((select 2 as v) union all (select 3 as v)) as q1

diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index ceac4aabf769c4efbff8fc39707a8d8866db4086..d60f1699cd8eee7b5114ae827b502bdf4b726109 100644 (file)
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1730,6 +1730,14 @@ select * from
     select * from (select 3 as z offset 0) z where z.z = x.x
   ) zz on zz.z = y.y;
 
+-- check dummy rels with lateral references (bug #15694)
+explain (verbose, costs off)
+select * from int8_tbl i8 left join lateral
+  (select *, i8.q2 from int4_tbl where false) ss on true;
+explain (verbose, costs off)
+select * from int8_tbl i8 left join lateral
+  (select *, i8.q2 from int4_tbl i1, int4_tbl i2 where false) ss on true;
+
 -- check handling of nested appendrels inside LATERAL
 select * from
   ((select 2 as v) union all (select 3 as v)) as q1