… machines? A: I covered this a bit during the session, but to provide a bit more commentary. There are…there are plenty of other MySQL and OS-level status variables that you might want to keep an eye on…-grant-tables and insert a few rows into an InnoDB table, but trying to run a simple mysqlslap just…
Post: PHP Sessions - Files vs Database Based
March 27, 2007 By 38 Comments
… same session at the same time. First of course means you may have your session data damaged because you will have lost session variables… old file based session behavior with MySQL Sessions ? If you have dedicated connection to session database and use Innodb tables for your session storage you…
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
… feature is controlled by the expand_fast_index_creation system variable which is OFF by default. Let’s look at each… TABLE OPTIMIZE TABLE is mapped to ALTER TABLE … ENGINE=InnoDB for InnoDB tables and thus, is just a special case of the… space when using expand_fast_index_creation. It is a session variable, so you can temporarily switch it off if you are…
Post: Undo area size restriction needed for Innodb
November 9, 2006 By 4 Comments
… today: InnoDB: 11 transaction(s) which must be rolled back or cleaned up InnoDB: in total 292735956 row operations to undo InnoDB: Trx… completed withing limited timeframe and catch development errors. Having is SESSION variable would allow to raise the limit if some large transaction…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…session_cache_missesblogpercona.commanual Ssl_session_cache_modeblogpercona.commanual Ssl_session_cache_overflowsblogpercona.commanual Ssl_session_cache_sizeblogpercona.commanual Ssl_session_cache_timeoutsblogpercona.commanual Ssl_sessions…
Post: What to tune in MySQL Server after installation
September 29, 2006 By 118 Comments
… created on disk. innodb_buffer_pool_size This is very important variable to tune if you’re using Innodb tables. Innodb tables are much… all of these are global variables. These variables depend on hardware and mix of storage engines, while per session variables are typically workload specific…
Post: Test Drive of Solid
September 22, 2006 By 5 Comments
…=’mysql’ where id=1; Session 2: mysql> begin; mysql> update test2 set names=’Solid’ where id=2; Session 1: mysql> update test2… proceed modifying them without causing deadlocks. For comparion here are InnoDB sessions: Test 1: Deadlock detection (deadlock is correctly detected): insert into…
Post: MySQL should have dynamic durability settings
April 8, 2008 By 4 Comments
If you’re using Innodb tables MySQL has innodb_flush_log_at_trx_commit variable which defines how durable your transactions are. If… product rating votes. What Innodb could do is at least to make innodb_flush_log_at_trx_commit a session variable, this is really where it belongs as decision how to commit transaction can be decided for each transaction separately in session…
Post: InnoDB's gap locks
March 27, 2012 By 15 Comments
… data to other sessions. How to troubleshoot gap locks? Is possible to detect those gap locks using SHOW ENGINE INNODB STATUS: —TRANSACTION… need to create locks to prevent that from happening. 2- innodb_locks_unsafe_for_binlog = 1. Disables the gap locks except… options is that the second one is a global variable that affects all sessions and needs a server restart to change its…
Post: 10+ Ways to Crash or Overload MySQL
November 13, 2007 By 20 Comments
…buffers such data until you have executed prepared statement. Innodb Table Cache Leak – Innodb never shrinks its internal table cache (data …all possibilities were validated. Session variables There is no restriction on how large you can set per connection variables for unprivileged user which…
