…from the buffer pool should be faster than getting them from the OS cache, which is another…. SSB Flight #4 There is one query in this flight, Q4.3…innodb_old_blocks_time=0 table_open_cache=2048 table_definition_cache=16384 …innodb_stats_persistent innodb_stats_auto_update=off [mysqld_safe] log-error=/…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
… another equivalent solution. If you’re talking about using a temporary table … storing another column, and reinitializing the sequence after making certain insert/update/delete … returned in a different order from what you specify in the query… at our events. The next one is in London on November 11…
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
…TABLE crashes MySQL There is yet another source of information about the table structure – InnoDB dictionary. Let’s review tables from… table‘s index. Which one? A table can…update | 6 | 1799 | 4 | 0 | +———-+—–+————-+——-+———+——+——+ So, we know all fields of the table…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…table SELECT * FROM old_table is done and then RENAME old_table to tmp_table, new_table to old_table and finally DROP tmp_table. Let’s see another…
Post: How adding another table to JOIN can improve performance ?
August 1, 2008 By 12 Comments
… exceptions 
The one I’m speaking about comes from the issue with …another table though why it does not work for multiple group remains question to check with MySQL Optimizer team UPDATE…another table to the join so the info table just has bunch of ref lookups: mysql> select * from g; +—–+ | …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…89 0.0022 1.00 0.01 UPDATE wp_options # 7 0x7AEDF19FDD3A33F1 0.1381 1… query executed against the wp_options table. Another thing to note is the last …Tables # SHOW TABLE STATUS FROM `wp_blog_one ` LIKE ‘wp_terms’\G # SHOW CREATE TABLE `wp_blog_one `.`wp_terms`\G # SHOW TABLE STATUS FROM `wp_blog_one…
Post: The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
… ON DUPLICATE KEY UPDATE query instances, and only one of them into table with AUTO_INCREMENT…Another table remained though. We used mk-table-sync –print as a diff tool for MySQL to see what is different in the tables…-digest to get sample read traffic from both master and slave. –sample=50 (or…
Post: Recovering from a bad UPDATE statement
October 19, 2012 By 5 Comments
…one row changed — you don’t need anything fancy to recover from this failure case and can just run another UPDATE…
Post: Full Text Search Webinar Questions Followup
August 24, 2012 By 5 Comments
…the result set of 20 rows from SphinxQL queries is merely the…-row updates. But you would still have to update the …the search would necessarily do table-scans. Jessy B. also asked:…one solution may include advanced features that are must-have for your application, but are not so important for another…
Post: How much space does empty Innodb table take ?
December 16, 2008 By 7 Comments
…NULL Create_time: 2008-12-16 20:43:31 Update_time: NULL Check_time: NULL Collation: utf8_general_…table‘s .idb file takes 128K from the start while we only see 16K of data+32K of index, so another… small tables. For example it will show 16K as average row size for table with one row: mysql> show table…
