drop database if exists a; create database a; use a; CREATE TABLE `marker_7173` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET latin7 COLLATE latin7_estonian_cs DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_5650` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET utf8 COLLATE utf8_estonian_ci DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_5634` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET cp932 COLLATE cp932_bin DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_2534` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET ucs2 COLLATE ucs2_romanian_ci DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_6019` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET utf8 DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_7853` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET utf8 COLLATE utf8_esperanto_ci DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_7887` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET swe7 COLLATE swe7_bin DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; CREATE TABLE `marker_6002` ( `c1` int(11) NOT NULL AUTO_INCREMENT, `c2` varchar(1000) CHARACTER SET hebrew COLLATE hebrew_bin DEFAULT NULL, `c3` bigint(20) DEFAULT NULL, `c4` bigint(20) DEFAULT NULL, PRIMARY KEY (`c1`) ) ENGINE=MyISAM; EXPLAIN EXTENDED ( SELECT `join_2_0`.`c1` FROM `marker_7173` AS `join_0_0`, `marker_5650` AS `join_1_0`, `marker_5634` AS `join_2_0`, `marker_2534` AS `join_3_0`, `marker_6019` AS `join_4_0`, `marker_7853` AS `join_5_0`, `marker_7887` AS `join_6_0`, `marker_6002` AS `join_7_0` WHERE `join_0_0`.`c1`=`join_1_0`.`c1` AND `join_1_0`.`c1`=`join_2_0`.`c1` AND `join_2_0`.`c1`=`join_3_0`.`c1` AND `join_3_0`.`c1`=`join_4_0`.`c1` AND `join_4_0`.`c1`=`join_5_0`.`c1` AND `join_5_0`.`c1`=`join_6_0`.`c1` AND `join_6_0`.`c1`=`join_7_0`.`c1` OR `join_0_0`.`c2`<'?' AND `join_1_0`.`c2`<'?' OR `join_2_0`.`c2`>'?' OR `join_3_0`.`c2`>'?' OR `join_4_0`.`c2`='?' XOR `join_5_0`.`c2`<>'?' OR `join_6_0`.`c2`<>'?' AND `join_7_0`.`c2`>='?' GROUP BY `join_3_0`.`c1`, `join_2_0`.`c1`, `join_7_0`.`c1`, `join_1_0`.`c1`, `join_0_0`.`c1`, `join_0_0`.`c1`); show warnings;