From eda80f09ffd016a9fc12fc89f14019d760d998c8 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 18 Oct 2003 16:52:15 +0000
Subject: [PATCH] Repair interaction between IN-join processing and subselect
pullup that I inadvertently broke a few days ago (per report from Sean
Thomas). Add regression test case to try to catch any similar breakage in
future.
---
src/backend/optimizer/plan/subselect.c | 15 ++++++-----
src/test/regress/expected/subselect.out | 36 +++++++++++++++++++++++++
src/test/regress/sql/subselect.sql | 18 +++++++++++++
3 files changed, 63 insertions(+), 6 deletions(-)
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index d7d25c09f80..11612f408c9 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.82 2003/08/08 21:41:51 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.83 2003/10/18 16:52:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -493,8 +493,8 @@ make_subplan(SubLink *slink, List *lefthand, bool isTopQual)
* If rtindex is 0, we build Params to represent the sub-select outputs.
* The paramids of the Params created are returned in the *righthandIds list.
*
- * If rtindex is not 0, we build Vars using that rtindex as varno. The
- * Vars themselves are returned in *righthandIds (this is a bit of a type
+ * If rtindex is not 0, we build Vars using that rtindex as varno. Copies
+ * of the Var nodes are returned in *righthandIds (this is a bit of a type
* cheat, but we can get away with it).
*/
static List *
@@ -525,8 +525,11 @@ convert_sublink_opers(List *lefthand, List *operOids,
te->resdom->restype,
te->resdom->restypmod,
0);
- /* Record it for caller */
- *righthandIds = lappend(*righthandIds, rightop);
+ /*
+ * Copy it for caller. NB: we need a copy to avoid having
+ * doubly-linked substructure in the modified parse tree.
+ */
+ *righthandIds = lappend(*righthandIds, copyObject(rightop));
}
else
{
@@ -735,7 +738,7 @@ convert_IN_to_join(Query *parse, SubLink *sublink)
/*
* Build the result qual expressions. As a side effect,
- * ininfo->sub_targetlist is filled with a list of the Vars
+ * ininfo->sub_targetlist is filled with a list of Vars
* representing the subselect outputs.
*/
exprs = convert_sublink_opers(sublink->lefthand,
diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out
index 5a2ef11c21b..f7b8297809f 100644
--- a/src/test/regress/expected/subselect.out
+++ b/src/test/regress/expected/subselect.out
@@ -165,3 +165,39 @@ from int8_tbl group by q1 order by q1;
4567890123456789 | 0.6
(2 rows)
+--
+-- Test cases to catch unpleasant interactions between IN-join processing
+-- and subquery pullup.
+--
+select count(*) from
+ (select 1 from tenk1 a
+ where unique1 IN (select hundred from tenk1 b)) ss;
+ count
+-------
+ 100
+(1 row)
+
+select count(distinct ss.ten) from
+ (select ten from tenk1 a
+ where unique1 IN (select hundred from tenk1 b)) ss;
+ count
+-------
+ 10
+(1 row)
+
+select count(*) from
+ (select 1 from tenk1 a
+ where unique1 IN (select distinct hundred from tenk1 b)) ss;
+ count
+-------
+ 100
+(1 row)
+
+select count(distinct ss.ten) from
+ (select ten from tenk1 a
+ where unique1 IN (select distinct hundred from tenk1 b)) ss;
+ count
+-------
+ 10
+(1 row)
+
diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql
index c2cde6ac207..5ff9d1cf875 100644
--- a/src/test/regress/sql/subselect.sql
+++ b/src/test/regress/sql/subselect.sql
@@ -75,3 +75,21 @@ SELECT '' AS eight, ss.f1 AS "Correlated Field", ss.f3 AS "Second Field"
select q1, float8(count(*)) / (select count(*) from int8_tbl)
from int8_tbl group by q1 order by q1;
+
+--
+-- Test cases to catch unpleasant interactions between IN-join processing
+-- and subquery pullup.
+--
+
+select count(*) from
+ (select 1 from tenk1 a
+ where unique1 IN (select hundred from tenk1 b)) ss;
+select count(distinct ss.ten) from
+ (select ten from tenk1 a
+ where unique1 IN (select hundred from tenk1 b)) ss;
+select count(*) from
+ (select 1 from tenk1 a
+ where unique1 IN (select distinct hundred from tenk1 b)) ss;
+select count(distinct ss.ten) from
+ (select ten from tenk1 a
+ where unique1 IN (select distinct hundred from tenk1 b)) ss;
--
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