by Ovais Tariq | Apr 28, 2014 | Insight for DBAs, MySQL
I have recently been involved in diagnosing the reasons behind OOM invocation that would kill the MySQL server process. Of course these servers were primarily running MySQL. As such the MySQL server process was the one with the largest amount of memory allocated.But... 
by Ovais Tariq | Jan 21, 2014 | Insight for DBAs, MySQL, Percona Services
The other day I was working on an issue where one of the slaves was showing unexpected lag. Interestingly with only the IO thread running the slave was doing significantly more IO as compared to the rate at which the IO thread was fetching the binary log events from... by Ovais Tariq | Oct 18, 2013 | Insight for DBAs, MySQL
Each day there is probably work done to improve performance of the InnoDB storage engine and remove bottlenecks and scalability issues. Hence there was another one I wanted to highlight: Scalability issues due to tables without primary keys This scalability issue is... by Ovais Tariq | Feb 1, 2013 | Insight for DBAs, Insight for Developers, MySQL
While most of the talk recently has mostly been around the new changes in MySQL 5.6 (and that is understandable), I have had lately some very interesting cases to deal with, with respect to the Metadata Locking related changes that were introduced in MySQL 5.5.3. It... by Ovais Tariq | Oct 12, 2012 | MySQL
Solid State Drive (SSD) have made it big and have made their way not only in desktop computing but also in mission-critical servers. SSDs have proved to be a break-through in IO performance and leave HDD far far behind in terms of Random IO performance. Random IO is... by Ovais Tariq | Jun 22, 2012 | Benchmarks, Insight for DBAs, MySQL
Suppose you have turned on innodb_file_per_table (which means that each table has its own tablespace), and you have to drop tables in a background every hour or every day. If its once every day then you can probably schedule the table dropping process to run during... by Ovais Tariq | May 31, 2012 | Benchmarks, Insight for DBAs, MySQL
MariaDB 5.3/5.5 has introduced a new join type “Hash Joins” which is an implementation of a Classic Block-based Hash Join Algorithm. In this post we will see what the Hash Join is, how it works and for what types of queries would it be the right choice. I... by Ovais Tariq | May 16, 2012 | Benchmarks, Cloud, Insight for DBAs, MySQL
I have been working for a customer benchmarking insert performance on Amazon EC2, and I have some interesting results that I wanted to share. I used a nice and effective tool iiBench which has been developed by Tokutek. Though the “1 billion row insert... by Ovais Tariq | Apr 4, 2012 | Benchmarks, Insight for DBAs, MySQL
This is the third blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is targeted at the join related optimizations introduced in the optimizer. These optimizations are... by Ovais Tariq | Mar 21, 2012 | Benchmarks, Insight for DBAs, MySQL
This is the second blog post in the series of blog posts leading up to the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. This blog post is aimed at the optimizer enhancement Multi Range Read (MRR). Its available in both MySQL 5.6 and MariaDB... by Ovais Tariq | Mar 12, 2012 | Benchmarks, Insight for DBAs, MySQL
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer... by Ovais Tariq | Dec 29, 2011 | Insight for DBAs, MySQL
Overview Profiling, analyzing and then fixing queries is likely the most oft-repeated part of a job of a DBA and one that keeps evolving, as new features are added to the application new queries pop up that need to be analyzed and fixed. And there are not too many... by Ovais Tariq | Oct 13, 2011 | MySQL
I have been working with a few customer cases and one interesting case popped up. The customer was facing a peculiar problem where the rows column in the EXPLAIN output of the query was totally off. The actual number of rows was 18 times more than the number of rows...
