Hi,

I have a simple table:

CREATE TABLE `cache_articles` (
cache_article_id int(10) unsigned NOT NULL auto_increment,
de_waregroup_1 varchar(60) NOT NULL,
de_waregroup_2 varchar(60) NOT NULL,
de_waregroup_3 varchar(60) NOT NULL,
de_waregroup_4 varchar(60) NOT NULL,
PRIMARY KEY (cache_article_id),
KEY de_waregroup_1 (de_waregroup_1),
KEY de_waregroup_2 (de_waregroup_2),
KEY de_waregroup_3 (de_waregroup_3),
KEY de_waregroup_4 (de_waregroup_4),
) ENGINE=MyISAM;

and a simple query:

EXPLAIN SELECT *
FROM `cache_articles`
WHERE de_waregroup_1 = ''
AND de_waregroup_2 = ''
AND de_waregroup_3 = ''

Shouldn't an index merge be done? It's not:

| 1 | SIMPLE | cache_articles | ref |
de_waregroup_1,de_waregroup_2,de_waregroup_3 | de_waregroup_1 |
62 | const | 28216 | Using where |

MySQL version is 5.0.32.

Regards,
André