But why the first ANALYZE TABLE half corrupted the table, and the second finished to corrupt the table (the second ANALYZE have been executed a few second after the first one) ? Moreover the sc_user is the kind of table which is changing so often. FYI, here is the behaviour of the server when the ANALYZE was running : | 88 | root | localhost | sc_2 | Query | 9 | | ANALYZE TABLE sc_product | 0.000 | | 145 | repl | 172.16.4.3:49541 | NULL | Binlog Dump | 475 | Master has sent all binlog to slave; waiting for binlog to be updated | NULL | 0.000 | | 218 | www-prod | sql-master:35879 | NULL | Sleep | 48 | | NULL | 0.000 | | 335 | root | localhost | NULL | Query | 0 | init | show processlist | 0.000 | | 899 | www-prod | cron-02.sc.lan:29654 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 903 | www-prod | www-14.sc.lan:46114 | sc_2 | Query | 0 | Waiting for table level lock | UPDATE `sc_product` SET `id` = 22076396, `id_big` = NULL, `parent_id` = NULL, `gen_year` = NULL, `pr | 0.000 | | 905 | www-prod | www-13.sc.lan:16006 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 910 | www-prod | www-11.sc.lan:21556 | sc_2 | Query | 1 | Waiting for table level lock | UPDATE `sc_product` SET `id` = 22101633, `id_big` = NULL, `parent_id` = NULL, `gen_year` = NULL, `pr | 0.000 | | 911 | www-prod | www-12.sc.lan:28156 | sc_2 | Query | 0 | Waiting for table level lock | UPDATE `sc_product` SET `id` = 22074921, `id_big` = NULL, `parent_id` = NULL, `gen_year` = NULL, `pr | 0.000 | | 916 | www-prod | www-10.sc.lan:42513 | sc_2 | Sleep | 1 | | NULL | 0.000 | | 1652 | www-prod | cron-01.sc.lan:23003 | sc_2 | Query | 7 | Waiting for table level lock | INSERT INTO `sc_product` (`subtype_id`, `label`, `state`, `flag_gen`, `date_last_update`, `gen_colle | 0.000 | | 2976 | www-prod | www-14.sc.lan:61886 | sc_2 | Query | 17 | Queried about 1130000 rows | SELECT * FROM `sc_param` AS `Parameters` LEFT JOIN `sc_param_index` AS `ParametersIndices` ON `Param | 0.000 | | 2990 | www-prod | www-13.sc.lan:31588 | sc_2 | Query | 17 | Queried about 1060000 rows | SELECT * FROM `sc_param` AS `Parameters` LEFT JOIN `sc_param_index` AS `ParametersIndices` ON `Param | 0.000 | | 3089 | www-prod | cron-02.sc.lan:29934 | sc_2 | Sleep | 1 | | NULL | 0.000 | | 3098 | www-prod | cron-01.sc.lan:23545 | sc_2 | Sleep | 2 | | NULL | 0.000 | | 3108 | www-prod | www-12.sc.lan:44763 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 3109 | www-prod | www-12.sc.lan:44768 | sc_2 | Sleep | 2 | | NULL | 0.000 | | 3112 | www-prod | www-10.sc.lan:59716 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 3114 | www-prod | www-10.sc.lan:59723 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 3116 | www-prod | www-11.sc.lan:37865 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 3118 | www-prod | www-13.sc.lan:32402 | sc_2 | Sleep | 1 | | NULL | 0.000 | | 3121 | www-prod | www-13.sc.lan:32411 | sc_2 | Query | 1 | Waiting for table level lock | UPDATE `sc_product` SET `id` = 22130445, `id_big` = NULL, `parent_id` = NULL, `gen_year` = NULL, `pr | 0.000 | | 3123 | www-prod | www-14.sc.lan:62690 | sc_2 | Sleep | 1 | | NULL | 0.000 | | 3125 | www-prod | www-14.sc.lan:62697 | sc_2 | Sleep | 0 | | NULL | 0.000 | | 3128 | www-prod | www-13.sc.lan:32487 | sc_2 | Query | 0 | Sending data | SELECT `ParametersIndices`.`id`, `ParametersIndices`.`product_id_key`, `ParametersIndices`.`contact_ | 0.000 | +------+-----------+----------------------+------+-------------+------+-----------------------------------------------------------------------+------------------------------------------------------------------------------------------------------+----------+ 65 rows in set (0.00 sec) And just after the ANALYZE TABLE : | 335 | root | localhost | NULL | Query | 0 | init | show processlist | 0.000 | | 899 | www-prod | cron-02.sc.lan:29654 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22085883 LIMIT 1 | 0.000 | | 903 | www-prod | www-14.sc.lan:46114 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22076396 LIMIT 1 | 0.000 | | 905 | www-prod | www-13.sc.lan:16006 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22141104 LIMIT 1 | 0.000 | | 910 | www-prod | www-11.sc.lan:21556 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22101633 LIMIT 1 | 0.000 | | 911 | www-prod | www-12.sc.lan:28156 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22074921 LIMIT 1 | 0.000 | | 916 | www-prod | www-10.sc.lan:42513 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22127172 LIMIT 1 | 0.000 | | 1652 | www-prod | cron-01.sc.lan:23003 | sc_2 | Query | 0 | Opening tables | UPDATE `sc_product` SET `id` = 22150705, `subtype_id` = 3, `label` = 'Rage of the Battlemage', `stat | 0.000 | | 3089 | www-prod | cron-02.sc.lan:29934 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22068259 LIMIT 1 | 0.000 | | 3108 | www-prod | www-12.sc.lan:44763 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22068289 LIMIT 1 | 0.000 | | 3112 | www-prod | www-10.sc.lan:59716 | sc_2 | Sleep | 1 | | NULL | 0.000 | | 3114 | www-prod | www-10.sc.lan:59723 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22072706 LIMIT 1 | 0.000 | | 3116 | www-prod | www-11.sc.lan:37865 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22072797 LIMIT 1 | 0.000 | | 3121 | www-prod | www-13.sc.lan:32411 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22130445 LIMIT 1 | 0.000 | | 3125 | www-prod | www-14.sc.lan:62697 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 22072915 LIMIT 1 | 0.000 | | 3142 | www-prod | www-11.sc.lan:38322 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 4870269 LIMIT 1 | 0.000 | | 3143 | www-prod | www-13.sc.lan:32853 | sc_2 | Query | 0 | Opening tables | SELECT * FROM `sc_product` AS `Products` WHERE `Products`.`id` = 411737 LIMIT 1 | 0.000 | +------+-----------+----------------------+------+-------------+------+-----------------------------------------------------------------------+------------------------------------------------------------------------------------------------------+----------+ 60 rows in set (0.00 sec) (the server was stuck with a lot of "opening tables" query for almost 2mn after the ANALYZE TABLE execution)