…EXCEPT a specified set of databases and tables. With this method, every event is …SHOW PROCESSLIST that might be a sign that trouble is brewing. Or if you watch your MySQL…MySQL world, except maybe MyISAM files on top of a clustered filesystem with an external lock manager. You might say that MySQL…
Post: ZFS on Linux and MySQL
May 24, 2013 By 17 Comments
… InnoDB, with MyISAM you’ll have to start the snapshot while holding a “flush tables with read lock” and… of random data that doesn’t compress well showed a compression ration of 1.70 with gzip-1…ZFS on Linux is a very interesting solution for MySQL backup servers. All backup solutions have an impact…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
… MyISAM table locks. Let me start with some examples. First lets run SELECT Query: —TRANSACTION 12303, ACTIVE 26 sec mysql tables in use 2, locked 0 MySQL… anything about MySQL level locks, so table locked on MySQL level with LOCK TABLES will not show up out there. Now you may spotted important difference between MyISAM and…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…table_definition_cacheblogpercona.commanual table_lock_wait_timeoutblogpercona.commanual Table_locks_immediateblogpercona.commanual Table_locks_waitedblogpercona.commanual table_open_cacheblogpercona.commanual table…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… getting field list from all tables) Reads though would not be blocked, ie there is no MYISAM like table lock priority problem with pending WRITE query blocks any READ queries to execute on the table. mysql> show processlist…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… enough for performance gotcha illustration purposes. The benchmark shows following results for MyISAM using MySQL 5.0.45 run on 4 Core System… only simple select query which should be executed without exclusive table locking. Even on 16 threads we’re getting performance worse than…
Post: MySQL Server Variables - SQL layer or Storage Engine specific.
June 8, 2006 By 14 Comments
…tables in MyISAM format in “mysql” database. Plus HEAP/MEMORY tables are used for temporary tables which may become MyISAM…table locks or if LOCK TABLES are used. So in practice this option is used for MyISAM and MEMORY tables. max_write_lock…timed_mutexes Show statistics by mutexes in SHOW MUTEX …
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 30 Comments
…table lock, the FLUSH TABLES WITH READ LOCK command itself will block until the other queries finish and all locks…mysql> show processlist; …TABLES WITH READ LOCK command finally acquires the lock, it must begin flushing data. This does not apply to all storage engines. However, MyISAM…
Comment: MySQL Server Memory Usage
September 1, 2006 By 21 Comments
…show_slave_hosts’, ’61′ ‘Com_show_slave_status’, ’13834′ ‘Com_show_status’, ’194766′ ‘Com_show_storage_engines’, ’0′ ‘Com_show_tables‘, ’2842′ ‘Com_show_variables’, ’176825′ ‘Com_show…mysql innodb_log_arch_dir=/var/log/mysql innodb_table_locks…
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
…instance, and I tried to show the minimal installation required for …replication, galera and built-in mysql replication are independent from each other…lock using FLUSH TABLES WITH READ LOCK. MyISAM support is experimental. Apart from some very special, edge cases, I would not recommend using MyISAM…
