…MySQL manual, especially the …innodb_change_bufferingblogpercona.commanual innodb_checksumsblogpercona.commanual innodb_commit_concurrencyblogpercona.commanual innodb_concurrency_ticketsblogpercona.commanual innodb_data_file_pathblogpercona.commanual Innodb_data_fsyncsblogpercona.commanual innodb…
Post: Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
November 20, 2012 By 17 Comments
… happens (which shouldn’t happen in normal Innodb), the transaction is rolled back, and this … node. A ‘local’ certification failure is only counted on the node that was the source … instead of a local transaction triggering the failure on commit, this is triggered by Galera replication threads …
Post: MySQL 4 to MySQL 5 Upgrade performance regressions
June 6, 2007 By 8 Comments
… group commit would trigger in MySQL 4.0 and large number of transactions in total so serializing them would make MySQL unable to… very strange behavior on 5.0 of MySQL being slow but few queries being “inside innodb” and potentially even empty queue. This is because bottleneck happens in commit phase which is not counted as “inside innodb“. I…
Post: Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs
February 23, 2012 By 3 Comments
…on CentOS. If you are using InnoDB, it is also important that …, if not, you could potentially trigger crash recovery when an LSN …mysql-bin.000022 | mysql mysql> select count(*) from salaries where emp_no = 10001; +———-+ | count(*) | +———-+ | 0 | +———-+ 1 row in set (0.00 sec) mysql…
Post: How much memory can MySQL use in the worst case?
February 12, 2009 By 17 Comments
…that’s not enough. Staying with InnoDB, we also need to count the data dictionary. This can …But let’s keep going! Any stored code (triggers, stored routines, etc) uses memory to execute;… 100); Query OK, 0 rows affected (2.34 sec) mysql> select get_lock(@a, 1); +—————–+ | get_lock(@a, 1) |…
Post: Can Innodb Read-Ahead reduce read performance ?
June 26, 2007 By 2 Comments
… reads. Pending normal aio reads are in fact counted in pages rather than distinct IO requests, so… sequential IO and so read-ahead is constantly triggered which makes all thread to wait on single…was adviseor in this project from MySQL AB side) – to improve how Innodb read-ahead works by having more …
Post: Debugging problems with row based replication
May 6, 2010 By 12 Comments
… format does offer advantages particularly if triggers or stored procedures are used,…AUTO_INCREMENT, PRIMARY KEY (`c1`) ) ENGINE=InnoDB; Query OK, 1 row affected (…count(*) from t1; +———-+ | count(*) | +———-+ | 65536 | +———-+ 1 row in set (0.02 sec) My test setup includes a MySQL…
Post: Are you designing IO bound or CPU bound application ?
December 20, 2006 By 10 Comments
… obvious but it is extremely important for MySQL Performance Optimization. In fact I probably have …to add counts for all messages, read messages etc, make sure they are updated (ie use triggers) … (data locality) also becomes very important – if Innodb tables are used having simply auto_increment …
Comment: How to calculate a good InnoDB log file size
December 22, 2008 By 38 Comments
mysql> SHOW GLOBAL VARIABLES LIKE ‘innodb_log_file_size’; +———————-+———–+ | Variable_name | Value | +———————-+———–+ | innodb_log_… transaction that seems to trigger the error and that… 1286113 (determined with SELECT COUNT(*)). The file containing the…
Comment: My Innodb Feature wishes
May 19, 2006 By 30 Comments
…. It is however not as trivial as it sounds as Innodb is multi versioning engine so each transaction could see different… fast way to get the count. You also could use counter table especially now with Triggers in MySQL 5.0 Yes I know…
