… the size of the partitions, the whole partition can be cached, as opposed to a single table, where probably only recently read records will be cached, resulting in more disc reads. 2. If you need to…. If you do queries on any other column, these could easily be quicker on a partitioned table, as Mysql can fire off…
Comment: Why MySQL Performance at Low Concurrency is Important
March 31, 2013 By 8 Comments
…/03/mysql-56-single-threaded-read-only.html. All of the conclusions assume a benchmark with fast (100 to 200 usecs) queries… a big win * 5.6 was ~9% slower for a cached database whether or not the PS was disabled
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… as MySQL Query Cache is most useful for complex expensive queries, for which tracking exact rows used from query syntax may be hard. Query Cache Storage Engines MySQL Query Cache now stores queries in local…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… MySQL Query Cache is – I’ve seen number of people 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. It does not cache the plan but…
Post: Return of the Query Cache, win a Percona Live ticket
August 26, 2011 By 4 Comments
… Live London ticket! But first, what’s new with the MySQL query cache? You may know that it still has the same fundamental… was still a query-cache single choke-point in the server. Now that’s gone. As of MySQL 5.5, the query cache mutex isn’t hit at all if query_cache_type is zero. We made…
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 5.0… Repeating queries from PHP instead we can learn the following about MySQL 5.0 Query Cache: Whitespace at the start of query does not block query from being cached. Moreover query with 2 spaces…
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
… for query cache lock | 0.000004 | | Waiting on query cache mutex | 0.000002 | | Sending data | 0.003407 | | Waiting for query cache lock | 0.000003 | | Waiting on query cache… was: why did MySQL need so many accesses to the query cache lock? The answer is in the way the query cache works. Simply stated…
Post: Beware large Query_Cache sizes
March 23, 2007 By 3 Comments
… had number of consulting projects with MySQL Query Cache being source of serious problems. One would see queries both for MyISAM and Innodb tables… ? If you set query_cache_size relatively high at 256MB or more. It can be seen worse if your query cache size is in Gigabytes. At the same time check how many queries do you have in cache – Qcache_queries_in_cache – if…
Post: How MySQL Query Cache works with Transactions
January 29, 2008 By 5 Comments
As MySQL Manual Says Query Cache works with transactions with Innodb tables but it does not … modified in transaction it becomes uncachable by query cache until that transaction is committed. Not only query cache can’t be used inside the… could use query cache until it is invalidated by committed transaction, however it was probably too hard to implement using current query cache infrastructure…
Post: MySQL Query Cache and prepared statements - support comming ?
March 15, 2007 By Leave a Comment
… post by Konstantin Osipov we should finally get Query Cache working with prepared statements in MySQL 5.1 The interesting thing Konstantin notes… fast prepared statements without query cache or no prepared statements with it. Would this make me use/advice Query Cache more ? Not really. There are enough of over limits with Query Cache which makes it best for…
