… column definition in the same order. In other words, it checks for duplicate keys, but not redundant ones. What is the… not -for example, if one of the two indexes was unique or a foreign key. This is the output of our… query optimizer and the MySQL version, we always recommend to check manually the optimizations proposed by Percona Toolkit. The MySQL server…
Post: Implementing SchemaSpy in your MySQL environment
June 4, 2013 By 2 Comments
… names, tables without indexes, columns flagged ‘nullable’ and ‘must be unique‘ (woops!), single column tables, incrementing column names in tables, and… actual SQL NULL value. This is basically a quick sanity check of your schema for any significant errors or items requiring…
Post: Announcing Percona XtraBackup 2.1.1 GA
May 15, 2013 By Leave a Comment
… open source solution, XtraBackup drives down backup costs while providing unique features for MySQL backup. The new 2.1.1 GA… inside tmpdir could cause SST to fail. Fixed by fix checking if xtrabackup_pid file exists once innobackupex starts, and try…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… the size of the transactions, which translates into number of unique key lookups into the certification index, which is a hash… coming from There are two global status variables you can check to see what flow control is happening: wsrep_flow_control…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 29 Comments
… way to load data (especially if you disable unique key checks and foreign key checks), I recommended against this. There are several problems…: time mysql -e “set foreign_key_checks=0; set sql_log_bin=0; set unique_checks=0; load data local infile ‘infile.txt… time mysql -e “set foreign_key_checks=0; set sql_log_bin=0; set unique_checks=0; load data local infile ‘/tmp/my…
Comment: Duplicate indexes and redundant indexes
September 22, 2006 By 38 Comments
… only with spatial extenrsions anyway. Speaking about UNIQUE it is interesting. If you have UNIQUE(A) and KEY(A,B) it is… to have index covered queries but It is other story. UNIQUE is both Index and constraint, but unfortunately they come together… prefix (A,B) unique. Currently it is not possible and one ether have to create extra index or do unique checking on application.
Post: Best kept MySQLDump Secret
March 23, 2012 By 13 Comments
…=@OLD_SQL_MODE */; /*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */; /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */; /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER…
Comment: Using MyISAM in production
November 10, 2009 By 36 Comments
… FIELDS PRIMARY KEY (`id`) ) ENGINE=INNODB DEFAULT CHARSET=latin1; SET UNIQUE_CHECKS=0; START TRANSACTION; — SOME MULTIPLE INSERTS KIND OF INSERT INTO…_inno( SELECT * FROM transferido LIMIT 100000,100000 ); –ETC. COMMIT; SET UNIQUE_CHECKS=1; ALTER TABLE transferido RENAME TO transferido_myisam; ALTER TABLE…
Post: Predicting how long data load would take
May 24, 2007 By 14 Comments
… depend on storage engines, for example MyISAM can build non-unique indexes by sort which is very fast and Innodb can… BTREE insertion. For Innodb SET UNIQUE_CHECKS=0 may be used to speed up load to tables with unique keys. So as you…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… transaction_isolationblogpercona.commanual transaction_prealloc_sizeblogpercona.commanual tx_isolationblogpercona.commanual unique_checksblogpercona.commanual updatable_views_with_limitblogpercona.commanual Uptimeblogpercona.commanual Uptime…
