…In my first post in this series, I described materialized views (MVs). An MV is essentially a cached result set at one point in…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 6 Comments
…mysql> select min(id),max(id) from words; +———+———+ | min(id) | max(id) | +———+———+ | 1 | 3088896 | +———+———+ 1 row in set (0.00 sec) How to factor numbers…
Post: Advanced index analysis with mk-index-usage
November 11, 2010 By 2 Comments
… in mk-index-usage to help you determine how indexes are used in …store the results in my MySQL sandbox instance. The new option is –save-results-database. …pingback)$’ AND comment_approved = ’1′ 1 row in set (0.00 sec) How about … want. The documentation includes a number of other canned queries you …
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 4 Comments
…number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in…mysql> SELECT COUNT(*) FROM test_table; — 3 Tickets Used +———-+ | COUNT(*) | +———-+ | 3 | +———-+ 1 row in set (0.00 sec) mysql> UPDATE test_table SET…
Post: Fishing with dynamite, brought to you by the randgen and dbqp
November 16, 2011 By Leave a Comment
… bug: mysql process crashes after setting innodb_… the randgen to determine the number, composition, and…number of tables: $tables = { rows => [1..50], partitions => [ undef ] }; The value in the ‘rows…in range(6): schema = schema_basename+str(i) query = “CREATE SCHEMA %s” %(schema) retcode, result_set…
Comment: To SQL_CALC_FOUND_ROWS or not to SQL_CALC_FOUND_ROWS?
August 29, 2007 By 53 Comments
… LIMIT 5;”, mysql uses index to determine number of rows to examine (through compound index on b and c) and returns a result set by picking physical data which takes some time (because columns are not included in index). I think use SQL_CALC_FOUND_ROWS in…
Post: Effect of adaptive_flushing
December 4, 2009 By 5 Comments
…resulted in a few changes which were recorded by the Cacti MySQL…determined by the number…in this? Sometimes tuning InnoDB settings can have quite unexpected results…. Setting innodb_adaptive_flushing ON seems better in…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…. First you should determine how your current MySQL installation was …set this to “full_scanâ€, while in order to get only those which use on-disk temporary storage for intermediate results…number of microseconds. Can be changed at run time with both SET SESSION and SET GLOBAL. min_examined_row…
