Join Optimizations in MySQL 5.6 and MariaDB 5.5

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 available in both MySQL 5.6 and MariaDB 5.5, and MariaDB 5.5

Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact

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 enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5

Profiling your slow queries using pt-query-digest and some love from Percona Server

This guide will get you up and running with how to identify the bottleneck queries using the excellent tool pt-query-digest. You will learn how to use and analyze the output returned by pt-query-digest. You will also learn some differences between slow query logging in various MySQL versions. Later on in the post I will also show you how to make use of the extra diagnostic data available with Percona Server.

EC2 firewall and security groups

EC2 includes a security feature that allows you to define groups with a set of firewall rules to restrict access. These groups are called security groups. This post deals with understanding how the security groups work and how to use them to restrict access based on IP as well as roles.

Slides of my talk on B+Tree Indexes and InnoDB

The slides of my talk on B+Tree Indexes and InnoDB are now available for download. This slide was presented during Percona Live London 2011. You can download the slides from here. There are many other interesting and informative talks that were presented during Percona Live London 2011, and I think you should definitely check them out, if you haven't. They are available here.

When EXPLAIN estimates can go wrong!

This is the title of my first blog post on MySQL Performance Blog. It deals with a customer case where 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 reported by MySQL in the output of EXPLAIN. Now this can be a real pain as MySQL uses “the number of rows” estimation to pick

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Understanding B+tree Indexes and how they Impact Performance

Indexes are a very important part of databases and are used frequently to speed up access to particular data item or items. So before working with indexes, it is important to understand how indexes work behind the scene and what is the data structure that is used to store these indexes, because unless you understand the inner working of an index, you will never be able to fully harness its power.

On Covering Indexes and Their Impact on Performance

The purpose of this post is to describe what covering indexes are and how they can be used to improve the performance of queries. People mostly use indexes to filter or sort the results but not much thought is given to actually reduce the disk reads by using proper indexes. So I will show you how to reduce disk reads and hence improve the performance of queries by utilizing indexes properly.