MySQL Bugs: #37371: CREATE TABLE LIKE merge loses UNION parameter

Bug #37371	CREATE TABLE LIKE merge loses UNION parameter
Submitted:	12 Jun 2008 15:17	Modified:	15 Jul 2010 19:50
Reporter:	Scott Noyes	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Merge storage engine	Severity:	S3 (Non-critical)
Version:	5.0.62	OS:	Any
Assigned to:	Dmitry Lenev	CPU Architecture:	Any

Description:
CREATE TABLE LIKE mergeTable; does not copy the UNION bit.

How to repeat:
mysql> SHOW CREATE TABLE tm\G
*************************** 1. row ***************************
       Table: tm
Create Table: CREATE TABLE `tm` (
  `id` int(11) default NULL,
  KEY `id` (`id`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1 UNION=(`t1`)
1 row in set (0.00 sec)

mysql> CREATE TABLE tm2 LIKE tm;
Query OK, 0 rows affected (0.00 sec)

mysql> SHOW CREATE TABLE tm2\G
*************************** 1. row ***************************
       Table: tm2
Create Table: CREATE TABLE `tm2` (
  `id` int(11) default NULL,
  KEY `id` (`id`)
) ENGINE=MRG_MyISAM DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

Suggested fix:
CREATE TABLE LIKE ought to copy the UNION too.

Hello!

The following patch http://lists.mysql.com/commits/51937, which among others fixes this problem, was pushed into mysql-6.1-fk tree. Eventually this tree is going to be merged into one of 6.x releases. Please let me know if there is a need for fixing this bug in one of earlier versions so this patch could be back-ported.

This bug was originally fixed in the 6.1-fk tree. The fix was later backported as part of the patch for Bug#42546 "Backup: RESTORE fails, thinking it finds an existing table".

This bug was therefore fixed in Ver 5.5.3, so I'm setting this bug to Documenting.

Test coverage (originally not backported) has now been backported in http://lists.mysql.com/commits/110795 and pushed to mysql-trunk-runtime (Ver 5.5.5).

Pushed into 5.5.5-m3 (revid:alik@sun.com-20100622130139-u05awgya93zvbsop) (version source revid:marko.makela@oracle.com-20100603095032-v5ptkkzt1bhz0m1d) (merge vers: 5.1.48) (pib:16)

Pushed into mysql-next-mr (revid:alik@sun.com-20100622130623-r7yhm89fz9n5t9nb) (version source revid:alik@sun.com-20100622130528-187gd949sa9b6pa6) (pib:16)

Noted in 5.5.3 changelog.

For CREATE TABLE ... LIKE with a MERGE source table that included a
UNION clause, that clause was omitted from the definition of the
destination table.