Bug #14308 server hang, with recursive view (after rename table)
Submitted: 26 Oct 2005 0:26 Modified: 27 Apr 2006 16:48
Reporter: Martin Friebe (Gold Quality Contributor) (SCA)
Status: Closed
Category:Server: Views Severity:S2 (Serious)
Version:5.0.15-nt/5.0.16 BK source OS:Microsoft Windows (windows (likely others)/Linux)
Assigned to: Oleksandr Byelkin Target Version:

[26 Oct 2005 0:26] Martin Friebe 
Description:
With "raname table" being allowed to rename views, it is now possible to create a
"recursive" view.

Selecting from such a view sends the server into an endless loop, slowly consuming memory

Repeat the sql below.

when executing the select be ready to kill your server. (windows with taskmanager, it does
not responnd to the service stop request)

How to repeat:
create table t1 (a int);
create view v1 as select * from t1;
create view v2 as select * from v1;
rename table t1 to t2;
rename table v2 to t1;

select * from v1;

Suggested fix:
check for recursion, while executing any action on the view.
[26 Oct 2005 2:42] Miguel Solorzano 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2 to server version: 5.0.16-debug

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> create table t1 (a int);
Query OK, 0 rows affected (0.04 sec)

mysql> create view v1 as select * from t1;
Query OK, 0 rows affected (0.00 sec)

mysql> create view v2 as select * from v1;
Query OK, 0 rows affected (0.01 sec)

mysql> rename table t1 to t2;
Query OK, 0 rows affected (0.00 sec)

mysql> rename table v2 to t1;
Query OK, 0 rows affected (0.00 sec)

mysql> 
mysql> select * from v1;
Aborted

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                        
                                               
23146 miguel    16   0  156m 114m 4532 S 99.9 24.3   0:35.26 mysqld                       
                                                 
23161 miguel    16   0  2056  964  752 R  0.7  0.2   0:00.07 top
[13 Dec 2005 14:18] Bugs System 
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/107
[29 Mar 2006 16:06] Konstantin Osipov 
Reviewed by email, approved with one note.
[13 Apr 2006 22:12] Bugs System 
A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/4942
[24 Apr 2006 8:47] Konstantin Osipov 
Pushed into 5.0.21, merged into 5.1.10
[25 Apr 2006 8:11] Oleksandr Byelkin 
pushed to 5.1.10, 5.0.21, 4.1.19 and 4.0.27
[25 Apr 2006 8:12] Oleksandr Byelkin 
oops sorry, it was pushed to pushed to 5.1.10 and 5.0.21
[27 Apr 2006 16:48] Paul DuBois 
Noted in 5.0.21, 5.1.10 changelogs.

Prevent recursive views caused by using <literal>RENAME
TABLE</literal> on a view after creating it. (Bug #14308)