…. MyISAM does not maintain checksum consistency during regular operations and is not ACID compliant. MyISAM and InnoDB may perform differently under concurrency, which… sort_buffer_size=128k read_rnd_buffer_size=8M join_buffer_size=8M default_tmp_storage_engine=myisam tmpdir=/dev/shm innodb…
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 be cause of scalablity and peformance… reason of problems is POSIX read-write locks, which are used to protect key_buffer from concurrent changes and called for each… and doing INSERT not often than disabling concurrent-insert with –skip-concurrent-insert can improve MyISAM performance. As I said the reason of…
Post: Using MyISAM in production
June 17, 2006 By 36 Comments
… ones. Concurrency. MyISAM uses table locks and has concurrent inserts which can go concurrently with selects. This is sometimes presented as great concurrency for inserts…: Log tables. Now Archive storage engine can be even better. Read only data, especially packed with myisampack. This can’t be…
Post: InnoDB vs MyISAM vs Falcon benchmarks - part 1
January 8, 2007 By 117 Comments
… to InnoDB and MyISAM. The second goal of benchmark was a popular myth that MyISAM is faster than InnoDB in reads, as InnoDB…-log-file-size=100M –innodb-thread-concurrency=8 –max-connections=1500 –table-cache=512 –net_read_timeout=30 –net_write_timeout=30… values. MyISAM scales very bad, and reason is the same as for READ_KEY_POINT queries. InnoDB is better than MyISAM by 2…
Post: Concurrent inserts on MyISAM and the binary log
May 14, 2008 By 7 Comments
… I had an interesting surprise with concurrent inserts into a MyISAM table. The inserts were not happening concurrently with SELECT statements; they were… this: Locked – read Low priority read lock But on INSERT…SELECT, you’ll see this: Read lock without concurrent inserts That read lock is what…
Post: Concatenating MyISAM files
November 19, 2012 By 5 Comments
… into MyISAM_table… select * from Innodb_table… would take about 10 days. The bottleneck was clearly the lack of concurrency on the read part from InnoDB and then the key management for MyISAM. The server has many… was easy to add more concurrency so I kicked off, from a script, insertions into 16 identical MyISAM files for distinct parts…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… NOT NULL, PRIMARY KEY (`id`), KEY `val` (`val`) ) ENGINE=MyISAM AUTO_INCREMENT=4097 Table t1 contains about 260,000…is copied to processing thread local storage on Key Read Request. This lock is per key cache so …2x in peak which happens to be at 4 concurrent threads. So there is still work to do in…
Post: MySQL: what read_buffer_size value is optimal ?
September 17, 2007 By 25 Comments
… performance and today I’ve discovered even read_buffer_size selection may be less than obvious… NOT NULL, `slack` varchar(50) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 1 row in set (…which was not considered – small buffers with high concurrency may mean more seeks and so worse performance…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
….commanual Compressionblogpercona.commanual concurrent_insertblogpercona.commanual connect_…myisam_sort_buffer_sizeblogpercona.commanual myisam_stats_methodblogpercona.commanual myisam_use_mmapblogpercona.commanual named_pipeblogpercona.commanual net_buffer_lengthblogpercona.commanual net_read…
Post: Test Drive of Solid
September 22, 2006 By 5 Comments
… and phantom reads in the repeatable read isolation level. Solid has OPTMISTIC (default) and PESSIMISTIC concurrency control, …from test2; +—-+———–+ | id | names | +—-+———–+ | 1 | Mysql | | 2 | Solid | | 3 | MyISAM | +—-+———–+ Session1: mysql> begin; Query OK, 0 rows …
