… This will not really change until MySQL Server implements Global Resource Management as otherwise you …mysql_stmt_send_long_data call – Server buffers such data until you have executed prepared statement. Innodb Table Cache…1000 variables in stored procedure and set 1M result set to each of them ? I …
Post: Query Profiling with MySQL: Bypassing caches
September 12, 2007 By 6 Comments
… MySQL Caches you can restart MySQL and this is the only way to clean all of the caches. You can do FLUSH TABLES to clean MySQL table cache (but not Innodb table meta data) or you can do “set global key_buffer_size=0; set global…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
… for large data sets. Larger sizes offer …MySQL Server crashes. Value 2 only cause data loss with full OS crash. table_cache – Opening tables can be expensive. For example MyISAM tables…cache hit ratio is lower than would justify having it enabled. Note: as you can see all of these are global…
Post: MySQL: Followup on UNION for query optimization, Query profiling
August 14, 2006 By 14 Comments
… ed4481336eb9adca222fd404fa15658e | | 888ba838661aff00bbbce114a2a22423 | +———————————-+ 2 rows in set (0.00 sec) mysql> explain SELECT sql_no_cache … to get global counters SHOW GLOBAL STATUS needs to…set (0.00 sec) We can however use UNION to avoid filesort of full table: mysql…
Post: MySQL MyISAM Active Active Clustering - looking for trouble ?
March 15, 2007 By 4 Comments
…? This configuration adds effectively global table locks besides extra overhead you get from external locking. Plus key cache have to be invalidated with…for large tables. Furthermore as I remember MySQL simply was not repairing corrupted tables in this configuration even if myisam_repair is set. …
Post: Solving INFORMATION_SCHEMA slowness
December 23, 2011 By 25 Comments
…mysql> select count(*),sum(data_length) from information_schema.tables; +———-+——————+ | count(*) | sum(data_length) | +———-+——————+ | 130 | 2856365892 | +———-+——————+ 1 row in set (1.08 sec) mysql> set global…
Post: Percona Server 5.1.58-12.9
August 17, 2011 By 2 Comments
…table to the cache, the server may evict and close another if the table cache is full. If the closed table…MySQL (Alexey Kopytov). Uninitialized values in the Slow Query Log patch. Bug Fixed: #794774 (Oleg Tsarev). Querying global_temporary_tables…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
…tables‘ ‘–enable-assembler’ ‘–enable-local-infile’ ‘–with-mysqld-user=mysql‘ ‘–with-unix-socket-path=/var/lib/mysql/mysql…SET SESSION and SET GLOBAL. Downloads msl patch for MySQL 5.0.45 msl patch for MySQL 5.0.51a msl patch for MySQL…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…tables and Created_disk_tmp_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table…
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
…Cache 365000 APC Cache 98000 File Cache 27000 Memcached Cache (TCP/IP) 12200 MySQL Query Cache (TCP/IP) 9900 MySQL Query Cache (Unix Socket) 13500 Selecting from table…caches to work, ie query cache enabled, memcached running, apc enabled for cli mode etc. Main PHP File: global…
