Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commitf796387

Browse files
committed
|From: Dan McGuirk <mcguirk@indirect.com>
||This patch fixes a backend crash that happens sometimes when you try to|join on a field that contains NULL in some rows. Postgres tries to|compute a hash value of the field you're joining on, but when the field|is NULL, the pointer it thinks is pointing to the data is really just|pointing to random memory. This forces the hash value of NULL to be 0.||It seems that nothing matches NULL on joins, even other NULL's (with or|without this patch). Is that what's supposed to happen?|
1 parent9848d36 commitf796387

File tree

1 file changed

+11
-1
lines changed

1 file changed

+11
-1
lines changed

‎src/backend/executor/nodeHash.c‎

Lines changed: 11 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -7,7 +7,7 @@
77
*
88
*
99
* IDENTIFICATION
10-
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.3 1996/07/26 20:03:21 scrappy Exp $
10+
* $Header: /cvsroot/pgsql/src/backend/executor/nodeHash.c,v 1.4 1996/08/19 01:52:36 scrappy Exp $
1111
*
1212
*-------------------------------------------------------------------------
1313
*/
@@ -527,6 +527,16 @@ ExecHashGetBucket(HashJoinTable hashtable,
527527
*/
528528
keyval=ExecEvalVar(hashkey,econtext,&isNull);
529529

530+
/*
531+
* keyval could be null, so we better point it to something
532+
* valid before trying to run hashFunc on it. --djm 8/17/96
533+
*/
534+
if(isNull) {
535+
execConstByVal=0;
536+
execConstLen=0;
537+
keyval= (Datum)"";
538+
}
539+
530540
/* ------------------
531541
* compute the hash function
532542
* ------------------

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp