…key_buffer, not “myisam_key_buffer” for example. The other excurse Monty used to make was – it is not really MyISAM specific. key_buffer…
Post: Using MyISAM in production
June 17, 2006 By 35 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… still watch out. Lack of row cache. MyISAM tables only have indexes cached in key_buffer while data is cached in OS cache… in certain cases by avoiding flushing dirty index blocks from key_buffer to disk, but it also comes at great danger if…
Post: MyISAM Scalability and Innodb, Falcon Benchmarks
October 12, 2007 By 10 Comments
… table locking. Even on 16 threads we’re getting performance worse than with single query. The problem in this case is key buffer… second confirmation that key_cache is a problem is benchmark run with disabled key_cache (=0). Results for MyISAM with key_buffer_size=0 Threads… is comparison of MyISAM Innodb and Falcon results in the graphical form: I’ve created bug, for MyISAM key cache contention issue and…
Post: Using Multiple Key Caches for MyISAM Scalability
November 26, 2008 By 8 Comments
…MyISAM Does Not Scale, or it does quite well – two main things stopping you is table locks… | cmd | +———————————————+ | SET GLOBAL test_a.key_buffer_size=39514112; | | SET GLOBAL test_b.key_buffer_size=28390400; | +———————————————+ 2 rows…
Post: Choosing innodb_buffer_pool_size
November 3, 2007 By 38 Comments
…buffer, locks which also take some time. Though it is not as critical – for most workloads if you will have your Innodb Buffer…buffers – query cache, key_buffer, mysql threads, temporary tables, per thread sort buffer…Buffer Pool selection for dedicated Innodb system. If you have fair amount of MyISAM…
Post: MyISAM concurrent insert
June 13, 2006 By 12 Comments
… reason of problems is POSIX read-write locks, which are used to protect key_buffer from concurrent changes and called for each processed…). Some results for MyISAM table, query SELECT id FROM sbtest WHERE id BETWEEN N AND N+20000, id – primary key. Boxes: Sun…-concurrent-insert can improve MyISAM performance. As I said the reason of bad scalability is rw-locks and currently MySQL developers are…
Comment: MySQL Limitations Part 3: Subqueries
October 25, 2010 By 20 Comments
… locks inside the system. Its most prevelent in thinks like the myisam key buffer cache, but there are still a lot of nasty big locks…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…key_buffer_sizeblogpercona.commanual key_cache_age_thresholdblogpercona.commanual key_cache_block_sizeblogpercona.commanual key_cache_division_limitblogpercona.commanual Key_read_requestsblogpercona.commanual Key_readsblogpercona.commanual Key…
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…’56479689′ ‘Sort_rows’, ’1344092495′ ‘Sort_scan’, ’935242′ ‘Table_locks_immediate’, ’895966639′ ‘Table_locks_waited’, ’20096′ ‘Threads_cached’, ’0′ ‘Threads_connected’, ’260′ ‘…_timeout=3600 wait_timeout=3600 key_buffer_size=32M # Only for MyISAM which isnt used. sort_buffer_size=2M query_cache_size=…
Comment: Database problems in MySQL/PHP Applications
November 6, 2006 By 12 Comments
… = /tmp/mysql.sock bind-address=10.234.94.71 skip-locking key_buffer_size = 2000M max_allowed_packet = 32M # table_cache=20M # open… tmp_table_size=1000M sort_buffer_size = 100M read_buffer_size = 100M read_rnd_buffer_size = 100M myisam_sort_buffer_size = 100M max_length_for…-updates [isamchk] key_buffer = 256M sort_buffer_size = 256M read_buffer = 2M write_buffer = 2M [myisamchk] key_buffer = 256M sort_buffer_size = 256M read_buffer = 2M write_buffer = 2M #[mysqlhotcopy…
