… this benchmark for MySQL Server 5.5.30, 5.6.11 and Percona Server 5.5.30 and check how these servers…. Percona Server 5.5 outperforms MySQL in about 2x times. Both MySQL 5.5.30 and MySQL 5.6.11 demonstrate notable drops… sync_binlog=0 max_connections=5000 table_open_cache=5000 table-definition-cache=1000 query_cache_size=0 query_cache_type=0 performance_schema=0 #56only…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
…16 tables with 5M rows each (about 23GB). So it makes sense to check if…_capacity = 2000 max_connections=5000 table_open_cache=5000 query_cache_type=OFF performance_schema=0…0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… cache lock | 0.000003 | | checking query cache for query | 0.000007 | | checking privileges on cached | 0.000003 | | checking permissions | 0.000005 | | sending cached …table that is already in the Table Cache, any query to a table that has a DDL operation waiting, will block. Why? Because MySQL…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
… sleep 60 done Check for Table Cache Related Allocations There are cases when MySQL will allocate a lot of memory for table cache, especially if you’re using large blobs. It is easy to check though. Run “FLUSH TABLES” and see whenever…
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 64 Comments
…cache for given table. Instead we could track versions for tables (increment each time table is updated) and check whenever version matches for all tables…
Post: Is there room for more MySQL IO Optimization?
January 3, 2013 By 11 Comments
… which need to be cached — system files, binary log, FRM files, MySQL MyISAM system tables etc. Starting MySQL 5.5 MySQL uses asynchronous IO which… more than buffer pool size and OS cache which is available. I run CHECK TABLE on this table which essentially performs data and indexes…
Post: MySQL Wish for 2013 - Better Memory Accounting
December 31, 2012 By 6 Comments
… for Innodb Buffer Pool or Query Cache but amount of memory used for example for Table Cache can be only guessed. Not only… memory allocation target, which could be something like “Prepared Statement Cache“, “Table Cache” etc. For global pools we need just global accounting, for… and help to get MySQL on the memory diet. It would be easy to extend QA suite to check for peak memory…
Post: ALTER TABLE: Creating Index by Sort and Buffer Pool Size
June 27, 2012 By 4 Comments
…used 10mil row table which would look as following in terms of data and index size: mysql> show table status …-06-27 13:04:56 Update_time: NULL Check_time: NULL Collation: latin1_swedish_ci Checksum: NULL…pool made very little memory available for OS cache, so index build process required more IO than…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
… MySQL manual, especially the option and variable reference table. …cache_hitsblogpercona.commanual Ssl_session_cache_missesblogpercona.commanual Ssl_session_cache_modeblogpercona.commanual Ssl_session_cache_overflowsblogpercona.commanual Ssl_session_cache_sizeblogpercona.commanual Ssl_session_cache…
Post: MySQL Crash Recovery
July 30, 2006 By 30 Comments
… good idea to run MySQL with myisam_recover option which will make sure all improperly closed MyISAM tables are checked first time it… use tiny script which moves out all MyISAM tables out of MySQL database directory, checks them with MyISAMchk and moves them back to… – If you restart MySQL server its caches (key_buffer, innodb_buffer_pool, query_cache,table_cache) are cleaned, so may be OS caches. This may reduce…
