[Alexander Pyhalov <a.pyhalov@postgrespro.ru>]

Hi.

Using the following patch I'm able to get
"ERROR:  variable not found in subplan target list"
on foreign join pushdown for update returning.
It seems that we generate Result node which has 7 vars in targetlist 
over Sort plan node, which has only 6 vars in targetlist.

So far not sure what causes this.

-- 
Best regards,
Alexander Pyhalov,
Postgres Professional

Attachments:

  [text/x-diff] costs_tweaks.diff (1.1K, ../cfb17bf6dfdf876467bd5ef533852d18@postgrespro.ru/2-costs_tweaks.diff)
  download | inline diff:
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 42735ae78a9..5eb387ef14f 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -1355,6 +1355,9 @@ INSERT INTO ft2 (c1,c2,c3)
 EXPLAIN (verbose, costs off)
 UPDATE ft2 SET c3 = 'bar' WHERE postgres_fdw_abs(c1) > 2000 RETURNING *;            -- can't be pushed down
 UPDATE ft2 SET c3 = 'bar' WHERE postgres_fdw_abs(c1) > 2000 RETURNING *;
+ALTER SERVER loopback OPTIONS (add fdw_startup_cost '10000.0');
+ALTER SERVER loopback OPTIONS (add fdw_tuple_cost '1.0');
+SET enable_nestloop TO false;
 EXPLAIN (verbose, costs off)
 UPDATE ft2 SET c3 = 'baz'
   FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
@@ -1364,6 +1367,9 @@ UPDATE ft2 SET c3 = 'baz'
   FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
   WHERE ft2.c1 > 2000 AND ft2.c2 === ft4.c1
   RETURNING ft2.*, ft4.*, ft5.*;
+RESET enable_nestloop;
+ALTER SERVER loopback OPTIONS (drop fdw_startup_cost);
+ALTER SERVER loopback OPTIONS (drop fdw_tuple_cost);
 EXPLAIN (verbose, costs off)
 DELETE FROM ft2
   USING ft4 INNER JOIN ft5 ON (ft4.c1 === ft5.c1)