…of rows must be joined together (Q4.1, Q4.2) but worse when small amounts of data are examined. Conclusion In…in memory, InnoDB almost always performs better, at least for this workload. Notes MySQL version used: 5…instances=16 metadata_locks_hash_instances=… symbolic-links=0 innodb_stats_persistent…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
…MySQL version < 5.5 as the datastore. There was another interesting case this time with how Active MQ uses MySQL when in HA mode. In…
Post: DROP TABLE and stalls: Lazy Drop Table in Percona Server and the new fixes in MySQL
June 22, 2012 By 33 Comments
…of it completely. In the new releases of MySQL (versions >= 5.5…lock on the latch protecting the AHI again Release the shared lock on the latch protecting the AHI Drop Table in Oracle MySQL >= 5.5…
Post: Innodb Table Locks
July 31, 2012 By 4 Comments
…row level locks or auto increment table level lock (mostly with MySQL 5.0 and older MySQL versions). MySQL level locks are entirely different story. Explicitly locking tables on MySQL…
Post: How much memory Innodb locks really take ?
July 13, 2006 By 11 Comments
…mysql> begin; Query OK, 0 rows affected (0.00 sec) mysql> select count(*) from sample where j like “5%” lock in share mode; +———-+ | count(*) | +———-+ | 102216 | +———-+ 1 row in…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
…come in MySQL 5.2 or even MySQL 5.1. I surely would like to see it sooner at least in more flexible community version. Relaxing Locks Row …Kinoshita did number of interesting benchmarks stress testing other areas in Innodb than buffer-pool which had it locking relaxed in latest MySQL 5.0 Hopefully …
Post: Avoiding auto-increment holes on InnoDB with INSERT IGNORE
November 29, 2011 By 8 Comments
… InnoDB tables on MySQL version 5.1.22 or newer? If so, you probably have gaps in your auto-increment … a single-row or multi-row INSERT/REPLACE uses a light-weight mutex instead of a table lock on AUTO-…1 and foo.name is null; Query OK, 0 rows affected (0.00 sec) Now check the auto_increment counter:…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
… I have started the development of an updated version of the patch. The basic …0.3s! # Query_time: 0.503016 Lock_time: 0.000048 Rows_sent: 56 Rows_examined: 1113 LOGGING OF THE REPLICATED STATEMENTS Normally MySQL…in production or on any important system! The patch is available for MySQL Community 5.0…
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
…of SHOW PROCESSLIST. (Laurynas Biveinis) Variable Changes Old status variable innodb_row_lock_numbers was renamed to innodb_current_row_locks…MySQL 5.0 or Percona Server versions prior to 5.1.7 could crash the server. (Yasufumi Kinoshita) MySQL bugs 56433 and 51325 – These MySQL…
Post: Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
…in AU$): The Raspberry Pi itself (about $36) Make sure to get the v2 (512MiB SDRAM) version…row-level locking, and foreign keys | YES | YES | YES | [...] mysql> SELECT “Hello World!” AS “Success!” \G *************************** 1. row *************************** Success!: Hello World! 1 row in set (0…
