… using Innodb tables probably got use to the fact Innodb tables perform non locking reads, meaning unless you use some modifiers such as LOCK IN…is not used you can enable innodb_locks_unsafe_for_binlog option, which will relax locks which Innodb sets on statement execution, which generally gives…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… 3 rows in set (0.00 sec) As you can see FLUSH TABLES WITH READ LOCK…tables) Reads though would not be blocked, ie there is no MYISAM like table lock…Innodb tables and you’re not actively changing users, stored procedures etc (which are stored in MyISAM tables…
Post: Table locks in SHOW INNODB STATUS
June 8, 2010 By 1 Comment
… root TABLE LOCK table `test/t1` trx id 0 4872 lock mode IX This output gives us an impression Innodb has taken table lock on test/t1 table… intention exclusive locks on the same table. What does Intention mean ? Just what it says. If Innodb sets intention exclusive lock on the table this means…
Post: Copying InnoDB tables between servers
July 31, 2009 By 11 Comments
…-innodb-tables-between…lock or shutdown server. To export table you need XtraBackup, and you can just specify table or table…set as followings. xtrabackup: innodb_data_home_dir = ./ xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend xtrabackup: innodb_log_group_home_dir = ./ xtrabackup: innodb…
Post: Thinking about running OPTIMIZE on your Innodb Table ? Stop!
December 9, 2010 By 18 Comments
…rows in set (0.04 sec) # This is just random SHA(1) hashes mysql> optimize table a; +——–+———-+———-+——————————————————————-+ | Table | …from using LOCK TABLES on Innodb table to ensure there is not ton of queries starting reading table with…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…innodb_status_fileblogpercona.commanual innodb_strict_modeblogpercona.commanual innodb_support_xablogpercona.commanual innodb_sync_spin_loopsblogpercona.commanual innodb_table_locksblogpercona.commanual innodb_thread_concurrencyblogpercona.commanual innodb…
Post: InnoDB: look after fragmentation
November 5, 2009 By 12 Comments
…=InnoDB Table has 11864696 rows and takes Data_length: 698,351,616 bytes on disk The problem is that after restoring table from… | 37864 | | Innodb_scan_pages_jumpy | 574 | +——————————+——-+ 2 rows in set (0.00 sec) and extended stats: # Query_time: 17.765369 Lock_time: 0…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… Opening tables | 0.000118 | | System lock | 0.000007 | | setup | 0.000027 | | creating table | 0.002255 | | After create | 0.000050 | | copy to tmp table…TABLE OPTIMIZE TABLE is mapped to ALTER TABLE … ENGINE=InnoDB for InnoDB tables and thus, is just a special case of the previous one: mysql> SET…
Post: SELECT LOCK IN SHARE MODE and FOR UPDATE
August 6, 2006 By 51 Comments
… in Innodb locking.? In my oppinion few rather important peices missing in Locking implementation of Innodb are: Lock table Innodb can lock tables but it will still need to set row level locks which is memory and CPU overhead. For some bulk operations it would be more efficient to use table locks… INTO MyISAMTable SELECT * FROM INNODBTable; – A lot of shared locks on Innodb table but no updates. Supporting MySQL hints “HIGH_PRIORITY” and “LOW…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… localhost root Updating update iz set pad=’a’ where i=1 *** (2) HOLDS THE LOCK(S): RECORD LOCKS space id 0 page no… number of tables locked by transactions. Innodb does not lock tables for normal operation so number of tables locked normally stays 0, unless it is ALTER TABLE or similar statement, or if LOCK TABLES…
