One of the very frequent cases with performance problems with MySQL is what they happen every so often or certain times… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 6 Comments
…. Making this change I could bring optimization, and full query execution time to less than 50ms. Low values, such as 3,4… further I found the following explanation from Timour Katchaounov in MySQL mailing list archives I have some recollection that there were… compatibility. In MySQL 5.6 things are likely to get even better handling joins of many tables as optimizer heuristics are improved…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… be low depending on your scenario. You can read more about the MRR optimization available in MySQL 5.6 here: http://dev.mysql.com… the MySQL config: optimizer_switch=’index_condition_pushdown=off’ optimizer_switch=’mrr=on’ optimizer_switch=’mrr_sort_keys=on’ (only on MariaDB 5.5) optimizer…
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
… external storage. 500MB/sec would be exceptional for traditional MySQL as MySQL optimizer with its nested loops joins does not favor sequential scans… be considered medium scale MySQL installations would get there. With MySQL we seems to prefer to run more low end server and storage… reasons for that. First because MySQL can be used for free we do not need to optimize the hardware for license costs…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… amazing MySQL manual, especially the option and …commanual long_query_timeblogpercona.commanual low_priority_updatesblogpercona.commanual lower_…tablesblogpercona.commanual optimizer_prune_levelblogpercona.commanual optimizer_search_depthblogpercona.commanual optimizer_switchblogpercona.commanual…
Post: Web Site Optimization: FrontEnd and BackEnd
June 26, 2008 By 12 Comments
… surprise there are more low hanging fruits on frontend part. We often deal with people with less than optimized backends with some… back end optimization applies here – if you spend 90% time running PHP code and only 10% fetching data from MySQL database it does not make sense to focus on MySQL optimization. If 90% is spent on…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
… been normally treated very quickly by MySQL. The moment you give someone access to MySQL Server, all MySQL Security guarantees is you can… ? This can be offset by keeping myisam_sort_buffer_size low, but then performance would suffer. Prepared Statements Number – Happily now… tree inside MySQL which of course depends on query size which is controlled by max_allowed_packet. However some MySQL optimizations such as…
Post: Troubleshooting MySQL Upgrade Performance Regressions
February 15, 2012 By Leave a Comment
… faster plan may be wrong plan from optimizer standpoint and updating stats may cause old MySQL Version to get slower plan instead… to check whenever it seems to be executing same on low level. FLUSH STATUS; SHOW STATUS can show whenever internal operation… binary or differently optimized binaries. When you’re about to file a bug or report the problem through MySQL support channel if…
Post: Economics of Performance Optimization
March 13, 2008 By 9 Comments
…and risks . First lets talk about optimizing application vs getting better hardware. With application optimization typically you have rather interesting relationship …of low hanging fruits which are easy to fix – adding couple of proper indexes or tuning couple of MySQL settings. When low hanging…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… to key_read_requests should be as low as possible, no more than 1:100″ or…or miss takes. If you approach application performance optimization from the standpoint of response time measurements, …the results to your IO system’s capabilities. MySQL doesn’t have good instrumentation for scientifically …
