…keys option it produced invalid SQL for cases when there was an explicitly named foreign key…keys from deferred key creation optimization. Bug fixed #1081016 (Alexey Kopytov). Percona Server for MySQL…_corrupt_table value checks by optimizing them … when userstat is disabled. Bug fixed #1128066 (Alexey…
Post: Percona Server 5.5.30-30.2 rerelease fixes non-restart issue
April 24, 2013 By Leave a Comment
…keys option it produced invalid SQL for cases when there was an explicitly named foreign key…keys from deferred key creation optimization. Bug fixed #1081016 (Alexey Kopytov). Percona Server for MySQL…_corrupt_table value checks by optimizing them … when userstat is disabled. Bug fixed #1128066 (Alexey…
Post: Hijacking Innodb Foreign Keys
January 2, 2012 By 2 Comments
… might be too expensive. MySQL Allows you for plenty of dirty tricks, and you can actually disable foreign keys to make it happen: CREATE… to satisfy foreign key conditions (have column child table is referencing and have it of proper type and indexed): mysql> set foreign_key_checks=0; Query…
Post: Eventual Consistency in MySQL
November 18, 2011 By 8 Comments
… that the enforcement of foreign keys incurs a significant performance overhead.1,2 MySQL allows us to set FOREIGN_KEY_CHECKS=0 to disable enforcement of RI when the overhead is too high. But if you later restore enforcement, MySQL does…
Post: On Character Sets and Disappearing Tables
June 21, 2012 By 1 Comment
… MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0″ before making schema changes, InnoDB will…: 150) Oops, we forgot to disable foreign key checking. No problem, right? Not exactly…. (root@localhost) [oops4]> set foreign_key_checks=0; Query OK, 0 rows affected…
Post: Best kept MySQLDump Secret
March 23, 2012 By 13 Comments
… | C | +——————–+ 3 rows in set (0.00 sec) mysql> select count(*) from A; +———-+ | count(*) | +———-+ … `C` DISABLE KEYS */; /*!40000 ALTER TABLE `C` ENABLE KEYS */; UNLOCK … SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */; /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;…
Comment: Unexpected problem with triggers and mysqldump
February 25, 2013 By 8 Comments
… using MySQL because of the peculiar way MySQL works (as mentioned above) There is no way to disable triggers nor any way to disable foreign key checks completely. http://bugs.mysql.com…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 29 Comments
… a fast way to load data (especially if you disable unique key checks and foreign key checks), I recommended against this. There are several problems with… file in one chunk: time mysql -e “set foreign_key_checks=0; set sql_log_bin=0; set unique_checks=0; load data local infile…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
…- innodb_locks_unsafe_for_binlog = 1. Disables the gap locks except for foreign-key constraint checking or duplicate-key checking. The most important difference between these…/doc/refman/5.1/en/innodb-locks-set.html. Conclusion MySQL uses REPEATABLE READ as the default isolation level so it…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
…keys that are part of a FOREIGN KEY constraint; mysqldump –innodb-optimize-keys ignores foreign keys because InnoDB requires a full table rebuild on foreign key…
