…MySQL internals can enlighten me here. – audit_record_objs : List of database objects (tables…opening new possibilities of extending MySQL‘s behavior in a way that, once set up, is transparent to users, and the McAfee MySQL…
Post: Percona XtraBackup 2.0.7 for MySQL available for download
May 6, 2013 By 1 Comment
… Software Repositories. Percona XtraBackup is the world’s only open-source, free MySQL hot backup software that performs non-blocking backups for… imported by ALTER TABLE IMPORT TABLESPACE on MySQL and Percona Server 5.6 as described in Exporting and Importing Tables guide. Bugs Fixed…. If there are thousands of tables and slow IO then XtraBackup can spend a lot of time opening all the tablespaces. Optimization has…
Post: Percona XtraBackup 2.1.0 'release candidate' for MySQL available for download
May 7, 2013 By Leave a Comment
… MySQL 5.6. This option can be used to produce 5.6-style metadata files, that can be imported by ALTER TABLE IMPORT TABLESPACE on MySQL and Percona Server 5.6 as described in Exporting and Importing Tables guide. Bugs Fixed…. If there are thousands of tables and slow IO then XtraBackup can spend a lot of time opening all the tablespaces. Optimization has…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…Open_filesblogpercona.commanual open_files_limitblogpercona.commanual Open_streamsblogpercona.commanual Open_table_definitionsblogpercona.commanual Open_tablesblogpercona.commanual Opened_filesblogpercona.commanual Opened_table_definitionsblogpercona.commanual Opened…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL 5.5.3 a statement that opened a table…Open%tables‘; +—————+——-+ | Variable_name | Value | +—————+——-+ | Open_tables | 30 | | Opened_tables…
Post: How to convert MySQL's SHOW PROFILES into a real profile
February 20, 2012 By 12 Comments
…database to demonstrate: mysql> SET profiling=1; mysql> pager cat > /dev/null mysql> SELECT * FROM…0.0001336667 | | Creating tmp table | 0.000548 | 0.32 | 1 | 0.0005480000 | | Opening tables | 0.000196 | 0.11 |…| 0.000002 | 0.00 | 1 | 0.0000020000 | | logging slow query | 0.000001 | 0.00 | 1 | 0….
Post: Slow DROP TABLE
June 16, 2009 By 21 Comments
… file removals can be painfully slow and cause a lot of random …Opening tables | select sql_no_cache * from other_table limit 1 | +—–+——+———–+——+———+——+—————-+————————————————+ I tried some alternative approaches to trick MySQL…
Post: table_cache negative scalability
November 16, 2009 By 23 Comments
… made updates to headers very slow. In the production systems with table headers not in OS …opened_tables) to 10/sec or less by using large table_cache you should do so. However if you have so many tables…MySQL 5.1, lets see how MySQL 5.4 behaves. MySQL 5.4.2 MySQL 5.4.2 has higher default table_open…
Post: How innodb_open_files affects performance
November 18, 2009 By 4 Comments
… keep open file descriptor when table is open – open table is purely logical state and appropriate .ibd file may be open or closed. Furthermore besides MySQL table_cache… – there is no any surprises such as surprised slow downs for replacing open files in the list. I guess Heikki knows how…
Post: MySQL 5.5 and MySQL 5.6 default variable values differences
February 21, 2013 By 8 Comments
…from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query: mysql [localhost] {msandbox…INSTANCES | 1 | 8 | | QUERY_CACHE_SIZE | 0 | 1048576 | | SLOW_QUERY_LOG_FILE | /mnt/data/sandboxes/msb_…values. I do not expect large impact here. table_open_cache is increased from 400 to 2000 by…
