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-rw-r--r--contrib/postgres_fdw/expected/postgres_fdw.out56
-rw-r--r--contrib/postgres_fdw/postgres_fdw.c16
-rw-r--r--contrib/postgres_fdw/sql/postgres_fdw.sql26
3 files changed, 95 insertions, 3 deletions
diff --git a/contrib/postgres_fdw/expected/postgres_fdw.out b/contrib/postgres_fdw/expected/postgres_fdw.out
index de4a1b6df86..020350fb379 100644
--- a/contrib/postgres_fdw/expected/postgres_fdw.out
+++ b/contrib/postgres_fdw/expected/postgres_fdw.out
@@ -2132,6 +2132,62 @@ SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM
1
(10 rows)
+-- bug #15613: bad plan for foreign table scan with lateral reference
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT ref_0.c2, subq_1.*
+FROM
+ "S 1"."T 1" AS ref_0,
+ LATERAL (
+ SELECT ref_0."C 1" c1, subq_0.*
+ FROM (SELECT ref_0.c2, ref_1.c3
+ FROM ft1 AS ref_1) AS subq_0
+ RIGHT JOIN ft2 AS ref_3 ON (subq_0.c3 = ref_3.c3)
+ ) AS subq_1
+WHERE ref_0."C 1" < 10 AND subq_1.c3 = '00001'
+ORDER BY ref_0."C 1";
+ QUERY PLAN
+---------------------------------------------------------------------------------------------------------
+ Nested Loop
+ Output: ref_0.c2, ref_0."C 1", (ref_0.c2), ref_1.c3, ref_0."C 1"
+ -> Nested Loop
+ Output: ref_0.c2, ref_0."C 1", ref_1.c3, (ref_0.c2)
+ -> Index Scan using t1_pkey on "S 1"."T 1" ref_0
+ Output: ref_0."C 1", ref_0.c2, ref_0.c3, ref_0.c4, ref_0.c5, ref_0.c6, ref_0.c7, ref_0.c8
+ Index Cond: (ref_0."C 1" < 10)
+ -> Foreign Scan on public.ft1 ref_1
+ Output: ref_1.c3, ref_0.c2
+ Remote SQL: SELECT c3 FROM "S 1"."T 1" WHERE ((c3 = '00001'::text))
+ -> Materialize
+ Output: ref_3.c3
+ -> Foreign Scan on public.ft2 ref_3
+ Output: ref_3.c3
+ Remote SQL: SELECT c3 FROM "S 1"."T 1" WHERE ((c3 = '00001'::text))
+(15 rows)
+
+SELECT ref_0.c2, subq_1.*
+FROM
+ "S 1"."T 1" AS ref_0,
+ LATERAL (
+ SELECT ref_0."C 1" c1, subq_0.*
+ FROM (SELECT ref_0.c2, ref_1.c3
+ FROM ft1 AS ref_1) AS subq_0
+ RIGHT JOIN ft2 AS ref_3 ON (subq_0.c3 = ref_3.c3)
+ ) AS subq_1
+WHERE ref_0."C 1" < 10 AND subq_1.c3 = '00001'
+ORDER BY ref_0."C 1";
+ c2 | c1 | c2 | c3
+----+----+----+-------
+ 1 | 1 | 1 | 00001
+ 2 | 2 | 2 | 00001
+ 3 | 3 | 3 | 00001
+ 4 | 4 | 4 | 00001
+ 5 | 5 | 5 | 00001
+ 6 | 6 | 6 | 00001
+ 7 | 7 | 7 | 00001
+ 8 | 8 | 8 | 00001
+ 9 | 9 | 9 | 00001
+(9 rows)
+
-- non-Var items in targetlist of the nullable rel of a join preventing
-- push-down in some cases
-- unable to push {ft1, ft2}
diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c
index 309f27ca856..1326fcf8226 100644
--- a/contrib/postgres_fdw/postgres_fdw.c
+++ b/contrib/postgres_fdw/postgres_fdw.c
@@ -893,6 +893,9 @@ postgresGetForeignPaths(PlannerInfo *root,
* baserestrict conditions we were able to send to remote, there might
* actually be an indexscan happening there). We already did all the work
* to estimate cost and size of this path.
+ *
+ * Although this path uses no join clauses, it could still have required
+ * parameterization due to LATERAL refs in its tlist.
*/
path = create_foreignscan_path(root, baserel,
NULL, /* default pathtarget */
@@ -900,7 +903,7 @@ postgresGetForeignPaths(PlannerInfo *root,
fpinfo->startup_cost,
fpinfo->total_cost,
NIL, /* no pathkeys */
- NULL, /* no outer rel either */
+ baserel->lateral_relids,
NULL, /* no extra plan */
NIL); /* no fdw_private list */
add_path(baserel, (Path *) path);
@@ -4243,7 +4246,7 @@ add_paths_with_pathkeys_for_rel(PlannerInfo *root, RelOptInfo *rel,
startup_cost,
total_cost,
useful_pathkeys,
- NULL,
+ rel->lateral_relids,
sorted_epq_path,
NIL));
}
@@ -4277,6 +4280,13 @@ postgresGetForeignJoinPaths(PlannerInfo *root,
return;
/*
+ * This code does not work for joins with lateral references, since those
+ * must have parameterized paths, which we don't generate yet.
+ */
+ if (!bms_is_empty(joinrel->lateral_relids))
+ return;
+
+ /*
* Create unfinished PgFdwRelationInfo entry which is used to indicate
* that the join relation is already considered, so that we won't waste
* time in judging safety of join pushdown and adding the same paths again
@@ -4367,7 +4377,7 @@ postgresGetForeignJoinPaths(PlannerInfo *root,
startup_cost,
total_cost,
NIL, /* no pathkeys */
- NULL, /* no required_outer */
+ joinrel->lateral_relids,
epq_path,
NULL); /* no fdw_private */
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 3e488e0ebe4..e424ebbe1d8 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -516,6 +516,32 @@ EXPLAIN (VERBOSE, COSTS OFF)
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
SELECT t1."C 1" FROM "S 1"."T 1" t1, LATERAL (SELECT DISTINCT t2.c1, t3.c1 FROM ft1 t2, ft2 t3 WHERE t2.c1 = t3.c1 AND t2.c2 = t1.c2) q ORDER BY t1."C 1" OFFSET 10 LIMIT 10;
+-- bug #15613: bad plan for foreign table scan with lateral reference
+EXPLAIN (VERBOSE, COSTS OFF)
+SELECT ref_0.c2, subq_1.*
+FROM
+ "S 1"."T 1" AS ref_0,
+ LATERAL (
+ SELECT ref_0."C 1" c1, subq_0.*
+ FROM (SELECT ref_0.c2, ref_1.c3
+ FROM ft1 AS ref_1) AS subq_0
+ RIGHT JOIN ft2 AS ref_3 ON (subq_0.c3 = ref_3.c3)
+ ) AS subq_1
+WHERE ref_0."C 1" < 10 AND subq_1.c3 = '00001'
+ORDER BY ref_0."C 1";
+
+SELECT ref_0.c2, subq_1.*
+FROM
+ "S 1"."T 1" AS ref_0,
+ LATERAL (
+ SELECT ref_0."C 1" c1, subq_0.*
+ FROM (SELECT ref_0.c2, ref_1.c3
+ FROM ft1 AS ref_1) AS subq_0
+ RIGHT JOIN ft2 AS ref_3 ON (subq_0.c3 = ref_3.c3)
+ ) AS subq_1
+WHERE ref_0."C 1" < 10 AND subq_1.c3 = '00001'
+ORDER BY ref_0."C 1";
+
-- non-Var items in targetlist of the nullable rel of a join preventing
-- push-down in some cases
-- unable to push {ft1, ft2}
generated by cgit v1.2.3 (git 2.46.0) at 2025-09-05 17:10:24 +0000