… MySQL 5.6 is to use a caching layer to store expensive result sets or objects. Some typical use cases include: Complicated query… 1 Box with http/php, 1 box with memcache or mysql started PHP script Zend framework libmemcached PECL module Zend_Cache_Backend_Libmemcached Here… (~.06 ms/op) MySQL Select showed 27% increase over InnoDB fetch (~.09 ms/op) This replaced $cache->load() with $db->query(“SELECT * FROM…
Comment: MySQL Partitioning - can save you or kill you
April 30, 2013 By 45 Comments
…There are _no_ parallel queries (within a single connection) anywhere in any ‘free’ variant of MySQL. PARTITIONs are …times. (Usually 4 of the 5 are cached from previous queries.) (Re #2) I have rambled on … details (and code) here: http://mysql.rjweb.org/doc.php/partitionmaint The third use case for …
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… 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…
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
… are: Cache Type Cache Gets/sec Array Cache 365000 APC Cache 98000 File Cache 27000 Memcached Cache (TCP/IP) 12200 MySQL Query Cache (TCP/IP) 9900 MySQL Query Cache (Unix … all caches to work, ie query cache enabled, memcached running, apc enabled for cli mode etc. Main PHP File: global.php file with…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… bug: http://bugs.mysql.com/bug.php?id=67647 Metadata locking behaves differently for queries that are serviced from the Query Cache, let’s see… for query 11; +——————————–+———-+ | Status | Duration | +——————————–+———-+ | starting | 0.000018 | | Waiting for query cache lock | 0.000003 | | checking query cache for query | 0.000007 | | checking privileges on cached | 0…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
… the results of a query in Memcache. When the cache “expires”, the contents must …_id, customer_name, sale_when; $ php convert.php demo < sales.sql CALL flexviews.create('demo...available for querying: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)); Query OK, …
Post: Caching techinques
August 8, 2006 By 11 Comments
… (instead of doing it from PHP). The other case when caching in files can be very helpful is caching data long term – ie… often. Cache Invalidate With this apporach you invalidate or remove objects in cache once underlying information is updated. This is how MySQL Query Cache works by removing all queries derived from the table…
Post: MySQL Prepared Statements
August 2, 2006 By 21 Comments
… sometimes buggy code. I had a lot of problems with PHP prepared statements. It is getting better but still it is… great future ahead for MySQL Prepared statements – many of the problems such as extra round trip, non working query cache or non working prepared statements for some of the statements as well as most of other problems can be fixed. MySQL…
Comment: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
… Oracle world, with my first exposure to the MySQL query cache, I had assumed it was caching query execution plans. In Oracle there’s a… find that MySQL was caching query result sets. Isn’t that what the InnoDB buffer cache was for? Perhaps it is because the query cache was… some limitations in MySQL around cursors, and that the parse, execute and fetch phases are only simulated in PHP & Perl libraries, and…
Post: mk-query-digest, query comments and the query cache
…the LAMP stack. Instrumentation-for-php collects information about the PHP process such as wall time, cpu time, mysql query times, etc, and …this test. You can enable query cache stripping in Percona Server at runtime: mysql> set global query_cache_strip_comments=’ON’; Query OK, 0 rows affected…