…MySQL community members at a single conference. The extra day added to this year’s conference …professional network. There are some great evening activities where you can network with the community: Monday features…and Expo pass, you can save 15% by using discount code PERCONA15 when you register. I …
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements for that…I understand that my PRIMARY KEY (`hid`,`mid`,`id`) where `id` is sequential, and `hid`,`mid` is …8M myisam_max_sort_file_size = 10G #myisam_max_extra_sort_file_size = 10G myisam_repair_threads = …
Comment: SimCity outages, traffic control and Thread Pool for MySQL
March 21, 2013 By 16 Comments
… maintainable way. Other examples of this have been where consultants or sales engineers who had skill and … to 20% slower overall, merely because of the extra syntax having been added in a sloppy way…. when working on Drizzle. Stored Procedures have their use today, but it’s not difficult to identify…
Post: Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
September 17, 2007 By 14 Comments
… | | 6950 | 290 | +——+———+ 11 rows in set (29.68 sec) Use of extra temporary table for buffering helps us to get result set…: 37748736 Extra: Using where; Using temporary; Using filesort 1 row in set (0.01 sec) mysql> explain select grp, count(*) cnt from dt where slack like…: 37748736 Extra: Using where; Using filesort 1 row in set (0.00 sec) As I forced FileSort execution method for GROUP BY by using SQL…
Post: Using index for ORDER BY vs restricting number of rows.
February 16, 2007 By 8 Comments
…. An extra problem comes from the fact MySQL prefers when it is possible to use index for further restriction and than using file…: 296338 Extra: Using where; Using filesort 1 row in set (0.00 sec) mysql> explain select * from goods force index(cat_id) where cat_id… Extra: Using where 1 row in set (0.00 sec) As you can see if given no hint MySQL will prefer to use index…
Post: Getting MySQL to use full key length
January 31, 2007 By 5 Comments
…: 8 ref: const,const rows: 1 Extra: Using where 1 row in set (0.00 sec) Where group_id key is defined as KEY… to be used to largest extent possible: mysql> explain SELECT thread_id FROM nn2_msg132.msg132 force index(group_id) WHERE group… key: group_id key_len: 12 ref: NULL rows: 51 Extra: Using where 1 row in set (0.00 sec) As you can…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
…: PRIMARY key: PRIMARY key_len: 3 ref: NULL rows: 30 Extra: Using where; Using index *************************** 2. row *************************** id: 1 select_type: SIMPLE table: info…: PRIMARY key: PRIMARY key_len: 3 ref: NULL rows: 30 Extra: Using where; Using index *************************** 2. row *************************** id: 1 select_type: SIMPLE table: info…
Post: Possible optimization for sort_merge and UNION ORDER BY LIMIT
September 18, 2007 By 10 Comments
…: c1 key: c1 key_len: 4 ref: const rows: 108112 Extra: Using where *************************** 2. row *************************** id: 2 select_type: UNION table: utest type…: c2 key: c2 key_len: 4 ref: const rows: 54268 Extra: Using where *************************** 3. row *************************** id: NULL select_type: UNION RESULT table: type…
Post: Joining on range? Wrong!
May 17, 2010 By 10 Comments
…: PRIMARY key: PRIMARY key_len: 98 ref: const rows: 1 Extra: Using where; Using index *************************** 2. row *************************** id: 1 select_type: SIMPLE table: p…: example_db.p.prd_id,const rows: 206494 Extra: Using where; Using index This query uses 7 bytes of `itm_prd_id__and__itm_order…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…_OrderDateKey key: NULL key_len: NULL ref: NULL rows: 5996539 Extra: Using where *************************** 2. row *************************** id: 1 select_type: SIMPLE table: dim_date…_DateKey rows: 2837 Extra: Using where 2 rows in set (0.00 sec) mysql> select * from information_schema.global_status where variable_name like…
