* 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 $
*
*-------------------------------------------------------------------------
*/
* 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 *
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
{
/*
* 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,
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)
+
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;