…from MySQL to do so. What is really bad is Parallel query…MySQL has very good stability track record, with exception of MySQL 5.0 it was typically safe to…the work is going on and it just takes time to get them all fixed. 5. Do not forget about the roots. MySQL…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…the query, the server could have died. The ORM should just be running the query, and if the query fails, then you know from the error code that the…the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, and so on. As with settings and status, these set the…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…the chance to parallelize. As you know, MySQL doesn’t do intra-query parallelization, so ETL jobs written to rely on SQL tend to get…the clicks column record the total, and the blue_clicks column record only blue clicks; to find out non-blue clicks you subtract one from the…
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 16 Comments
…the improved MySQL 5.5 partitioning options which work directly on columns without the need to use TO_DAYS. To accommodate my partitioning schema I modified the queries to use the…records. This table is partitioned by month which means that MySQL can use partition pruning to reduce the…
Post: Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
…from MySQL Cluster, which is more special-purpose, this is probably the best general-purpose way to get…query against these three sets of stats to find the top tables on the active server and left-join those against the tables on the…
Post: MySQL Slow query log in the table
May 31, 2007 By Leave a Comment
…queries coming to the top of the list rather than in the end. If you want to get new queries in the end you can do SELECT * FROM (SELECT * FROM…to sort records by physical position quickly without need to have indexes would be quite handy I also should tell log table implementation in MySQL…
Post: ORDER BY ... LIMIT Performance Optimization
September 1, 2006 By 93 Comments
…from the index can be used to satisfy order by, index however will not be helpful to check c=5 (unless it is index covered query…table: mysql> explain select test.i from test, test t where test.i=5 and test.k=t.k order by t.k limit 5…
Post: Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs
February 23, 2012 By Leave a Comment
…the salaries tables from the employees database! (Oops, I can have an angry mob of employees who may not get their salaries on time!). mysql> delete from…
