… MyISAM for everything!. MyISAM may be good for raw performance, but there are limitations which MyISAM imposes that are difficult to work with. MyISAM does not maintain checksum consistency during regular operations and is not ACID compliant. MyISAM…_log_buffer_size=32M innodb_buffer_pool_instances=16 metadata_locks_hash_instances=32 table_open_cache_instances=8 sort_buffer…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
… the MySQL world, except maybe MyISAM files on top of a clustered filesystem with an external lock manager. You might say that…
Post: ZFS on Linux and MySQL
May 24, 2013 By 17 Comments
… with InnoDB, with MyISAM you’ll have to start the snapshot while holding a “flush tables with read lock” and the flush…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… view on using MyISAM in production. For me it is not only about table locks. Table locks is only one of MyISAM limitations you…, each may allocate myisam_sort_buffer_size and MySQL could crash or go swapping. Second – table will be locked while repair is… updated, and you might not know which ones. Concurrency. MyISAM uses table locks and has concurrent inserts which can go concurrently with…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
…) unsigned NOT NULL, PRIMARY KEY (`id`), KEY `val` (`val`) ) ENGINE=MyISAM AUTO_INCREMENT=4097 Table t1 contains about 260,000 records… performance gotcha illustration purposes. The benchmark shows following results for MyISAM using MySQL 5.0.45 run on 4 Core System… change to key cache locking was done so disk IO is not done while lock is held, while lock is still held when…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
… and rightfully so as Innodb table locking is a bit more complicated than traditional MyISAM table locks. Let me start with some examples… 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 Innodb when it comes to Table Level Locks. For MyISAM tables running UPDATE query on the table is essentially equivalent to locking…
Post: How fast is FLUSH TABLES WITH READ LOCK?
April 24, 2010 By 30 Comments
… READ LOCK command finally acquires the lock, it must begin flushing data. This does not apply to all storage engines. However, MyISAM does…. As a result, a system that has a lot of MyISAM data might have a lot of dirty blocks in the… WITH READ LOCK will complete quickly. In some cases, it is unavoidable. This includes backing up a mixture of MyISAM and InnoDB…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… it works. Even though with general lock compatibility guidelines Read Lock should not conflict with another Read Lock, it does for this statement… though would not be blocked, ie there is no MYISAM like table lock priority problem with pending WRITE query blocks any READ… procedures etc (which are stored in MyISAM tables anyway) you can consider using –no-lock option with Percona Xtrabackup. Many other tools…
Post: Moving from MyISAM to Innodb or XtraDB. Basics
November 22, 2010 By 2 Comments
… have hidden dependencies of MyISAM table lock behavior in your applications, also check if your application handled deadlocks well. MyISAM will not produce… mk-upgrade Feature Differences – There are some feature differences between MyISAM and Innodb though well it is typically easily spotted by… MyISAM it is often for people to do updates in small chunks, almost row by row to avoid holding table lock for…
Post: MyISAM concurrent insert
June 13, 2006 By 12 Comments
Arjen posted a good note about MyISAM concurrent-insert features, though I should mention concurrent-insert can … user-space (Solaris) or kernel-space (Linux). Some results for MyISAM table, query SELECT id FROM sbtest WHERE id BETWEEN N…-concurrent-insert can improve MyISAM performance. As I said the reason of bad scalability is rw-locks and currently MySQL developers are…
