…on customer case today I ran into interesting problem – query joining about 20 tables (thank you ORM by joining all tables… to check the optimizer performance. Solution for this problem …number of tables. I was wondering if 0 is automatic selection why do we have value of 62 being default in MySQL…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…table participating in the joins are read, and then for each of these rows an index lookup is performed on the second table… of MySQL 5.5. MariaDB 5.5 is quite slow as compared to both MySQL 5.5 and MySQL…first obvious improvement is shown by the high numbers of Innodb_buffer_pool_read_ahead when the …
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… and then instead of point primary key lookups, a range lookup is performed on the primary …against base table, the number of these point primary key lookups will be depend on the number of rows … performing the benchmark on IO bound workload, mentioned above. Counter Name MySQL 5.5 MySQL 5.6 MySQL…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a… optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take… such as range scans, where index parts after the part on which range condition is applied cannot be used for filtering…
Post: Announcing Percona XtraBackup 2.0.0 GA
April 4, 2012 By 11 Comments
… utilities, which also had a number of other limitations (e.g…table). Percona XtraBackup now supports streaming incremental backups. In previous versions streaming backups were performed…MySQL Conference and Expo (register now!). Specifically, there are the following sessions at the conference on…
Comment: Should you move from MyISAM to Innodb ?
March 10, 2012 By 53 Comments
…MySQL community are snobbish about using…, InnoDB brings a lot of cons to the table which are missing in MyISAM…on a system crash is going to be a show stopper – you should not use MyISAM. If you have a huge number of concurrent writes and selects and query performance must be …
Post: Using VIEW to reduce number of tables used
September 28, 2007 By 12 Comments
… to reduce number of tables dramatically – merging say 1000 of users to the same table as VIEWs …on views, specially INSTEAD OF triggers so you could write triggers to perform insert inserts to base tables instead of… of the view so would not be available even if MySQL would support triggers on VIEWs…
Post: How number of columns affects performance ?
September 28, 2009 By 10 Comments
… with dynamic row format table with many columns. But is it because of large number of columns or dynamic format on its own is slave ? I have tested yet another table structure: CREATE TABLE `t1v1` ( `t1… it comes to in memory full table scan. P.S Tests were done on MySQL 5.4.2 on Intel(R) Xeon(R) CPU…
Post: Is your MySQL Application having Busy IO by Oracle Measures ?
January 8, 2012 By 1 Comment
… costs. With Oracle license costs based on number of CPUs we want to make sure … table and data sizes in MySQL can be painful, lacking online operations to alter table, …MySQL is getting better and better handling large scale systems (both in terms of performance and operationally) and as MySQL…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… constraints on what types of …book, High Performance MySQL 2nd Edition…of tables, but at this point I should have identified a handful of tables that really matter. That’s why I save this part of…of the analysis we do. A lot of times, customers will tell us up front to limit the work to some number of…
