Hello Sanja, Igor,
Could you please review the below? The new code, Item_cache::walk() passes the
main testsuite and fixed the bug, however I'm concerned it may have
implications that I am not aware of.
----- Forwarded message from Sergey Petrunya -----
From: Sergey Petrunya
To: commits@mariadb.org
X-Mailer: mail (GNU Mailutils 1.2)
Date: Tue, 21 Feb 2012 01:50:51 +0400 (GST)
Subject: [Commits] Rev 3275: BUG#920132: Assert trx->n_active_thrs == 1
failed at que0que.c line 1050 in
file:///home/psergey/dev2/5.5-look5/
At file:///home/psergey/dev2/5.5-look5/
------------------------------------------------------------
revno: 3275
revision-id: psergey@askmonty.org-20120220215050-ovuvi8qigyidenum
parent: psergey@askmonty.org-20120220210822-6yumujmervtemmwy
committer: Sergey Petrunya
branch nick: 5.5-look5
timestamp: Tue 2012-02-21 01:50:50 +0400
message:
BUG#920132: Assert trx->n_active_thrs == 1 failed at que0que.c line 1050
- MySQL 5.5 introduced caching of constant items by means of
wrapping them in Item_cache_XXX objects. If a subquery was wrapped
in this cache, it could end up being pushed down by ICP.
- The fix is to add Item_cache::walk() which lets ICP to see that
the cache item has a subquery inside it, and disable pushdown for this case.
=== modified file 'mysql-test/r/innodb_icp.result'
--- a/mysql-test/r/innodb_icp.result 2012-01-13 14:50:02 +0000
+++ b/mysql-test/r/innodb_icp.result 2012-02-20 21:50:50 +0000
@@ -808,5 +808,34 @@
1478
SET optimizer_switch=@save_optimizer_switch;
DROP TABLE t1,t2;
+#
+# BUG#920132: Assert trx->n_active_thrs == 1 failed at que0que.c line 1050
+#
+CREATE TABLE t1 ( a INT )
+ENGINE=InnoDB;
+INSERT INTO t1 VALUES (7),(7);
+CREATE TABLE t2 ( b VARCHAR(1) );
+INSERT INTO t2 VALUES ('j'),('v');
+CREATE TABLE t3 (
+c INT, d VARCHAR(1), e VARCHAR(1),
+KEY (d,c)
+) ENGINE=InnoDB;
+INSERT INTO t3
+VALUES (6,'w','w'),
+(1,'v','v'),(7,'s','s'),(4,'l','l'),
+(7,'y','y'),(0,'c','c'),(2,'i','i'),
+(9,'h','h'),(4,'q','q'),(0,'a','a'),
+(9,'v','v'),(1,'u','u'),(3,'s','s'),
+(8,'z','z'),(1,'h','h'),(8,'p','p'),
+(6,'e','e'),(3,'i','i'),(6,'y','y');
+SELECT *
+FROM t1 INNER JOIN t2 INNER JOIN t3
+ON d = b
+WHERE
+NOT EXISTS ( SELECT * FROM t3 )
+OR a = c
+ORDER BY e;
+a b c d e
+DROP TABLE t1,t2,t3;
set optimizer_switch=@innodb_icp_tmp;
set storage_engine= @save_storage_engine;
=== modified file 'mysql-test/t/innodb_icp.test'
--- a/mysql-test/t/innodb_icp.test 2011-07-08 14:46:47 +0000
+++ b/mysql-test/t/innodb_icp.test 2012-02-20 21:50:50 +0000
@@ -12,6 +12,39 @@
--source include/icp_tests.inc
+--echo #
+--echo # BUG#920132: Assert trx->n_active_thrs == 1 failed at que0que.c line 1050
+--echo #
+CREATE TABLE t1 ( a INT )
+ ENGINE=InnoDB;
+INSERT INTO t1 VALUES (7),(7);
+
+CREATE TABLE t2 ( b VARCHAR(1) );
+INSERT INTO t2 VALUES ('j'),('v');
+
+CREATE TABLE t3 (
+ c INT, d VARCHAR(1), e VARCHAR(1),
+ KEY (d,c)
+) ENGINE=InnoDB;
+INSERT INTO t3
+ VALUES (6,'w','w'),
+ (1,'v','v'),(7,'s','s'),(4,'l','l'),
+ (7,'y','y'),(0,'c','c'),(2,'i','i'),
+ (9,'h','h'),(4,'q','q'),(0,'a','a'),
+ (9,'v','v'),(1,'u','u'),(3,'s','s'),
+ (8,'z','z'),(1,'h','h'),(8,'p','p'),
+ (6,'e','e'),(3,'i','i'),(6,'y','y');
+
+SELECT *
+FROM t1 INNER JOIN t2 INNER JOIN t3
+ ON d = b
+WHERE
+ NOT EXISTS ( SELECT * FROM t3 )
+ OR a = c
+ORDER BY e;
+
+DROP TABLE t1,t2,t3;
+
set optimizer_switch=@innodb_icp_tmp;
set storage_engine= @save_storage_engine;
=== modified file 'sql/item.h'
--- a/sql/item.h 2012-02-15 17:08:08 +0000
+++ b/sql/item.h 2012-02-20 21:50:50 +0000
@@ -3901,6 +3901,12 @@
return example->is_expensive_processor(arg);
}
virtual void set_null();
+ bool walk(Item_processor processor, bool walk_subquery, uchar *arg)
+ {
+ if (example && example->walk(processor, walk_subquery, arg))
+ return TRUE;
+ return (this->*processor)(arg);
+ }
};
_______________________________________________
commits mailing list
commits@mariadb.org
https://lists.askmonty.org/cgi-bin/mailman/listinfo/commits
----- End forwarded message -----
--
BR
Sergei
--
Sergei Petrunia, Software Developer
Monty Program AB, http://askmonty.org
Blog: http://s.petrunia.net/blog
Sergei Petrunia