… MySQL configuration, queries and hardware, even though fixing these does help in many cases. Whatever powerful and well tuned system you have… too much in this case throttling by having relatively short queries and introducing “sleeps” between them can be a good idea…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… give you a simple example. Suppose you have the following query executed on the InnoDB table: SELECT non_key_column FROM… is choosing the query execution plan, is not sufficiently tuned and it is recommended to turn this off. The query used is: select… be incremented by TWO. It does not actually mean that queries with MRR are performing badly. The interesting thing is that…
Comment: Should you move from MyISAM to Innodb ?
March 10, 2012 By 53 Comments
… have a huge number of concurrent writes and selects and query performance must be consistently fast in this use case – you… of MyISAM which includes consistently faster query speeds, tables which are easily maintained, is more easily tuned and a system that will…
Comment: Should you move from MyISAM to Innodb ?
March 9, 2012 By 53 Comments
… 90% of my tables to innodb and currently going into queries and db optimization. Could someone really confirm where should i… from MyIsam. Will this be better once i tuned InnoDb settings? and add query cache? Thanks a lot for all the great…
Comment: MariaDB 5.3 is released as GA!
March 6, 2012 By 17 Comments
Don’t forget that Timour and Sergei are giving a 3 hour tutorial on MariaDB 5.3 (and 5.5?) and MySQL 5.6 optimizers: http://www.percona.com/live/mysql-conference-2012/sessions/improving-mysqlmariadb-query-performance-through-optimizer-tuning
Post: Tuning InnoDB Concurrency Tickets
May 24, 2010 By 4 Comments
……” What this means from a practical perspective is that each query is allocated 500 tickets when it begins executing. Each time… to determine how many concurrency tickets a query uses, making this parameter notoriously difficult to tune. It is important to note that…. It really comes down to the importance of the applicable queries. Imagine those 900-row SELECT statements were actually 10,000…
Post: What's required to tune MySQL?
July 27, 2011 By 4 Comments
… the following: The hardware The server configuration The workload The queries The schema design (table design, data types, indexing, etc) The…. For example, you may receive suggestions about reindexing, or changing queries, or even changing the way that the application uses the… configuration alone. [1] I prefer to avoid the word “tuning,” because database tuning is an activity that can be done endlessly, with…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 116 Comments
… goal is not to have threads created in normal operation. query_cache_size If your application is read intensive and you… session variables are typically workload specific. If you have simple queries there is no reason to increase sort_buffer_size even… so may decrease performance. I normally leave per session variable tuning to second step after I can analyze workload. P.S…
Comment: Beware of MyISAM Key Cache mutex contention
January 12, 2010 By 10 Comments
… and apache servers as well. At first I did standard tuning and query tuning but it seemed to make it worse! from once… processes showed in issue periods multiple copies of the same query, sometimes with also same parameters, and on OS side I… said. Still, Still! Sometimes we get 20/30 parallel identical queries at once that can raise the load to 8, and…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
… improve query cache manageability and make stats available this can even be done by external script which can have application-specific tunings to prioritize which queries are more important to refresh for given applications…
