… 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_write_requestsblogpercona.commanual Key…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… like “key%”; +————————+———+ | Variable_name | Value | +————————+———+ | Key_blocks_not_flushed | 6516 | | Key_blocks_unused | 0 | | Key_blocks_used | 7248 | | Key_read_requests | 2051451 | | Key_reads | 198208 | | Key_write_requests | 469220 | | Key_writes…
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…’ ‘Delayed_writes‘, ’0′ ‘Flush_commands’, ’5′ ‘Handler_commit’, ’19092941′ ‘Handler_delete’, ’0′ ‘Handler_discover’, ’0′ ‘Handler_read_first’, ’1100773′ ‘Handler_read_key…’, ’12524′ ‘Handler_write‘, ’292923929′ ‘Key_blocks_not_flushed’, ’0′ ‘Key_blocks_unused’, ’28987′ ‘Key_blocks_used’, ’1332′ ‘Key_read_requests‘, ’1552507′ ‘Key_reads’, ’1654′ ‘Key_write_requests‘, ’114303′ ‘Key_writes‘, ’1346′ ‘Max…
Comment: What to tune in MySQL Server after installation
September 5, 2008 By 116 Comments
… are the my server ‘SHOW STATUS’ output; Key_read_requests 9490927 Key_reads 72073 Key_write_requests 678314 Key_writes 430602 Open_tables 561 Open_files 278 Thanks…
Comment: Why MySQL could be slow with large tables ?
November 14, 2008 By 139 Comments
…_tables 5,274 Created_tmp_files 37 k Key_reads 4,226 Key_write_requests 380 k Key_writes 367 k Sort_merge_passes 18 k…
Post: What MySQL buffer cache hit rate should you target
June 29, 2006 By 5 Comments
… as – how busy were drives with concurrent requests, how random were these reads/writes, how good was OS or SAN cache hit…. For example if single query is issuing 100+ random IO requests which are not cached by OS or SAN this is… is done. In partuclar you should be looking at Key_reads and Key_writes for MyISAM tables (note this does not include row…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…we have similar information about last failed foreign key constraint: ———————— LATEST FOREIGN KEY ERROR ———————— 060717 4:29:00 Transaction: …request (read thread) I/O thread 3 state: waiting for i/o request (write thread) Pending normal aio reads: 0, aio writes:…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
… posts about 64 page read requests per a readahead. The InnoDB buffer is 256 page read requests for the aio read thread… page which is being requested via read-ahead. Q27 If my workload has a hi amount of concurrent writes to about 6…/s, 15979.01 non-hash searches/s HT: Strange, primary key equality searches should work through the adaptive hash index! What…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…The interesting question it brings – how many read-ahead requests can be queued at once. Q13: Is there … would also need also to write not-modified pages if this will get sequential write. Say if we have…, in the same order in the foreign key and the referenced key (this same order condition could be …
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 93 Comments
…task to launch a DOS attack – request page with some large number from…id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | …there are some differences. I should write another article about ORDER BY without…
