… secondary keys from deferred key creation optimization. Bug fixed #1081016 (Alexey Kopytov). Percona Server for MySQL was built with YaSSL which could… query which opened that table. Bug fixed #1127008 (Sergei Glushchenko). Fix for bug #1070856 introduced a regression in Percona Server for MySQL…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… more sense to configure MySQL as if it were using SSD storage or to just use an optimized HDD storage configuration? After creating a vCache device with the default configuration, I started with a baseline HDD configuration for MySQL… join_buffer_size = 4M thread_cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft_min_word_len = 4 thread…
Post: How to find MySQL queries worth optimizing ?
September 11, 2012 By 6 Comments
… find out queries which should be optimized. By looking at pt-query-digest report it is easy to find slow queries or queries which cause… which are found and returned up to the top level MySQL part for processing are counted the Rows_examined remains zero… is the easy way to see if query is worth optimizing ? – see how many rows query sends after group by, distinct and aggregate…
Post: MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
… the webinar: “Learn How MySQL 5.6 Makes Query Optimization Easier” for more tips on the 5.6 optimizer[/caption] While preparing the webinar… technique is available, this is always preferred over the ICP optimization: mysql> EXPLAIN SELECT role_id FROM cast_info WHERE role_id…-party, independent and technical opinion about the new features of MySQL query planner? Are you not yet familiar with terms like MRR…
Post: Percona MySQL Webinar: Really Large Queries: Advanced Optimization Techniques, Feb. 27
February 18, 2013 By 2 Comments
…”] Really Large Queries: Advanced Optimization Techniques: Wednesday, February 27, 2013 10 a.m. PST[/caption] Do you have a query you never dared… discuss filling the gap between reading explain output and optimizing really large queries. Practical techniques used to address real-world situations will…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… helpful for MySQL Performance optimization tasks but there are number of things you need to know. First let me clarify what MySQL Query Cache… being confused, thinking MySQL Query Cache is the same as Oracle Query Cache – meaning cache where execution plans are cached. MySQL Query Cache is not…
Post: MySQL Limitations Part 3: Subqueries
October 25, 2010 By 21 Comments
… queries to table b. This is because MySQL rewrites the query to make the inner query dependent on the outer query, which could be an optimization in some cases, but de-optimizes the query…
Post: Review of MySQL 5.6 Defaults Changes
October 8, 2012 By 10 Comments
… posted the great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there are a lot… – 64K or even more would be good default. query_cache_size = 1M Query cache remains off by default but default size is… have in the phones these days, I made in my Optimizing MySQL Configuration Webinar were heard 
Post: MySQL Query Cache WhiteSpace and comments
March 20, 2008 By 9 Comments
… post on MySQL Query Cache Gerry pokes me as I’m all wrong and both comments and whitespace are fixed in MySQL 5… which just does the same query. I did this as command line client is known to optimize queries sometimes by skipping “unnecessary” comments. So here is the command line run: mysql> select /* my little comment…
Post: Logging MySQL queries from the client instead of the server
February 2, 2011 By 2 Comments
The “slow query log” is the single most valuable way to examine query execution on your MySQL server. Queries are logged with timing information… nothing to do with the task you’re trying to optimize or analyze. You might also be interested in gathering data… commands, for example. But with mk-query-digest’s built-in ability to decode the MySQL wire protocol, it is certainly the…
