June 19, 2013

Post: Bug#12704861

November 20, 2011 By 1 Comment

… that is fixed in MySQL 5.1.60. I’ll repeat here the full documentation from the release notes:… files. The two obvious recommendations to help avoid hitting such bugs: don’t use autoextend and create …to such bugs. For completeness, I’ll include the full text of Marko’s commit message for the fix …

Filed Under: MySQL

Post: Sphinx search performance optimization: attribute-based filters

January 15, 2013 By 11 Comments

… are basically one of two kinds: a) full text b) attributes Speaking in MySQL terms, Full text columns are always indexed and using the very… | 5 | | time | 0.096 | | keyword[0] | great | | docs[0] | 200084 | | hits[0] | 216948 | +—————+——–+ 6 rows in set (0.00 sec) Solution…

Filed Under: Insight for Developers, MySQL Tagged With: , ,

Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 1

October 15, 2009 By 16 Comments

… getting a really solid # of hits in memcached, but the # of writes in MySQL coupled with the still large … we have 4GB of memory allocated to memcached (full dataset fits ): Here you can see that our … a row in another table based on a text field ( called email address ). Seems simple enough right? …

Filed Under: Benchmarks, Cloud and NoSQL, MySQL Tagged With: , ,

Post: MySQL Query Cache

July 27, 2006 By 70 Comments

…problem I should have started with full page caching rather than MySQL level caching but it is other …and cursors Query Cache works with query text and want full result set at once. In prepared statements…cached. Query Cache efficiency would be Qcache_hits/(Com_select+Qcache_hits). As you can see we …

Filed Under: Insight for DBAs Tagged With:

Post: Shard-Query adds parallelism to queries

November 15, 2010 By 18 Comments

… OLTP workloads. In fact, both Percona Server and MySQL 5.5.7rc have numerous performance improvements which… the added feature of supporting aggregation. Then I hit upon the idea of taking SQL constructs like…I’ll post a follow-up when I do. — Full Disclosure — This is a text file containing the …

Filed Under: Insight for Developers, MySQL Tagged With: , , , ,

Comment: MySQL Server Memory Usage

September 1, 2006 By 21 Comments

…Qcache_free_memory’, ’10272736′ ‘Qcache_hits‘, ’14774371′ ‘Qcache_inserts’, ‘…status’, ‘NULL’ ‘Select_full_join’, ’0′ ‘Select_full_range_join’, ’0…mysql.sock pid-file=/var/run/mysql/mysql.pid datadir=/db/disk2/mysql/data log-bin=/var/log/mysql/log log-slow-queries=/var/log/mysql…alot of text. Could …

Filed Under: Insight for DBAs Tagged With: , ,

Post: Living with backups

November 6, 2008 By 28 Comments

…some nightly batch job that just dumps all MySQL tables into a text file or ordinarily copies the binary files…by random “garbage” for no good reason. Since the hit ratio becomes worse as the cache is being …the file with O_DIRECT up to the last full block and then only perform a regular cached read…

Filed Under: Insight for DBAs Tagged With: , ,