…to the table, and populate the rows you want… making certain insert/update/delete operations. If…a different order from what you specify …index. Example: WHERE (last_name, first_name) = (‘Karwin’, …MySQL to scan the `title` table first, grouping by kind_id in index order. This made the first table…
Post: Follow these basics when migrating to Percona XtraDB Cluster for MySQL
May 1, 2013 By 10 Comments
… MySQL is a hot thing …updates is REQUIRED You need to have log_slave_updates enabled on the cluster node acting as async slave for replicated events from…tables. You can still try by filtering MyISAM tables though if you can leave them behind. Lastly… async master can use ROW based binlog format as …
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL…table with a row for each stat; there are just a few hundred rows. When a player makes an achievement, your application updates this table…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…. The last few…MySQL. PARTITIONs are scanned one at a time. (Please provide specific references if you find otherwise.) I would argue that single-row queries (SELECT, INSERT, DELETE, UPDATE…row (non-partitioned) table will, at worst, hit the disk only 5 times. (Usually 4 of the 5 are cached from…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…rows from the table with the old structure to the table with the new structure and will only wait at the last…
Post: When Does InnoDB Update Table Statistics? (And When It Can Bite)
October 6, 2011 By 7 Comments
…: db1 Last_errno: 0 Killed: 0 # Query_time: 12.277786 Lock_time: 0.000068 Rows_sent: 294 Rows_examined: 294 Rows_affected: 0 Rows_read… seconds to update all the tables‘ statistics. Luckily, this can be controlled with Percona Server with the variable innodb_stats_auto_update (from MySQL Community…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
…last…table. Instead we could track versions for tables (increment each time table is updated) and check whenever version matches for all tables…from “MySQL Market Players” – Oracle, MariaDB, Drizzle, Percona Server, will allocate resources to implement at least some portion of items from…
Post: Predicting Performance improvements from memory increase
August 7, 2008 By 6 Comments
… anyway. Interesting enough because of MySQL scaling issues it is also … how do we predict the benefit from increasing the memory and so cache … for example bunch of transactions updating single row in the table. Having such workload … reports are typically done for last few months. Basically in such …
Post: Edge-case behavior of INSERT...ODKU
October 27, 2012 By 6 Comments
…update last_modified=NOW(); Query OK, 2 rows affected (0.00 sec) (root@localhost) [test]> select * from update_test; +—-+———-+———+———————+ | id | username | host_id | last…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
…mysql> select * from flexviews.mview_table where mview_id= flexviews.get_id(‘demo’,'dashboard_customer_sales’)\G *************************** 1. row *************************** mview_table…
