May 18, 2013

Heikki Tuuri Innodb answers – Part I

Its almost a month since I promised Heikki Tuuri to answer Innodb Questions. Heikki is a busy man so I got answers to only some of the questions but as people still poking me about this I decided to publish the answers I have so far. Plus we may get some interesting follow up questions [...]

Using GROUP BY WITH ROLLUP for Reporting Performance Optimization

Quite typical query for reporting applications is to find top X values. If you analyze Web Site logs you would look at most popular web pages or search engine keywords which bring you most of the traffic. If you’re looking at ecommerce reporting you may be interested in best selling product or top sales people. [...]

Read Buffers, mmap, malloc and MySQL Performance

Monty Taylor posted interesting investigation of the fact read_buffer_size variable affects connection speed. This is not something you would expect right ? me too. Not only global user data is expected to be cached on startup but even if it is not why would you do full table scan to fetch single user information ? [...]

SHOW INNODB STATUS walk through

Many people asked me to publish a walk through SHOW INNODB STATUS output, showing what you can learn from SHOW INNODB STATUS output and how to use this info to improve MySQL Performance. To start with basics SHOW INNODB STATUS is command which prints out a lot of internal Innodb performance counters, statistics, information about [...]

Descending indexing and loose index scan

Comments to my previous posts, especially this one by Gokhan inspired me to write a bit about descending indexes and about loose index scan, or what Gokhan calls “better range” support. None of these are actially related to Innodb tables in general – these are features MySQL should get for all storage engines at some [...]