Fix oversight in join removal patch: we have to delete the removed relation

from SpecialJoinInfo relid sets as well.  Per example from Vaclav Novotny.

2 files changed, 20 insertions, 0 deletions

diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 5fd7d79b45d..6dfc710be01 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -2525,6 +2525,20 @@ explain (costs off)
  Seq Scan on a
 (1 row)
 
+-- check optimization of outer join within another special join
+explain (costs off)
+select id from a where id in (
+	select b.id from b left join c on b.id = c.id
+);
+         QUERY PLAN         
+----------------------------
+ Hash Semi Join
+   Hash Cond: (a.id = b.id)
+   ->  Seq Scan on a
+   ->  Hash
+         ->  Seq Scan on b
+(5 rows)
+
 rollback;
 create temp table parent (k int primary key, pd int);
 NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "parent_pkey" for table "parent"
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index d627973a091..8657636757a 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -588,6 +588,12 @@ explain (costs off)
   SELECT a.* FROM a LEFT JOIN (b left join c on b.c_id = c.id)
   ON (a.b_id = b.id);
 
+-- check optimization of outer join within another special join
+explain (costs off)
+select id from a where id in (
+	select b.id from b left join c on b.id = c.id
+);
+
 rollback;
 
 create temp table parent (k int primary key, pd int);