…ALTER TABLE test add column c char(32) default ‘dummy_text’; session3 > show processlist; +—-+———-+———–+——+———+——+———————————+————————————————————-+ | Id | User | Host | db | Command…
Post: Find and remove duplicate indexes
June 20, 2012 By 9 Comments
…mysql> alter table t add index(name); mysql> alter table t add index(name); mysql> alter table t add index(name); mysql> show create table t\G [...] KEY `name` (`name`), KEY `name_2` (`name`), KEY `name_3` (`name`) [...] MySQL…
Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!
December 9, 2010 By 18 Comments
…in primary key order as well as get better feel for primary key and index pages and so using less space, it is just OPTIMIZE TABLE…in set (4 min 5.52 sec) mysql> alter table a add key…commands…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…table. If you query date ranges most of the time, you should define the primary key as…in advance. What about partitioning in MySQL…ALTER TABLE — a typical reason to think about master-master with failover and failback for maintenance. As…
Post: Advanced index analysis with mk-index-usage
November 11, 2010 By 2 Comments
…PRIMARY,fud26_msg_i_a | 5971938384822841613 | 2 | +————————————+—————————————————+——————————————+——+ So the primary key on a table in…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…In MySQL 5 number of Innodb performance counters were exported and now available in SHOW STATUS output. Most of them are same as…tables locked normally stays 0, unless it is ALTER TABLE or similar statement, or if LOCK TABLES was used. In…
Post: Percona testing: Quick test clusters with kewpie!
January 13, 2012 By Leave a Comment
…mysql -uroot –protocol=tcp –port=9317 test Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id…mysql> create table t1 (a int not null auto_increment, primary key(a)); Query OK, 0 rows affected (0.11 sec) mysql…in set (0.00 sec) mysql> exit Bye Should you wish to alter…
