May 21, 2013

How InnoDB handles REDO logging

Xaprb (Baron) recently blogged about how InnoDB performs a checkpoint , I thought it might be useful to explain another important mechanism that affects both response time and throughput – The transaction log.

Ultimate MySQL variable and status reference list

I am constantly referring to the amazing MySQL manual, especially the option and variable reference table. But just as frequently, I want to look up blog posts on variables, or look for content in the Percona documentation or forums. So I present to you what is now my newest Firefox toolbar bookmark: an option and [...]

Thinking about running OPTIMIZE on your Innodb Table ? Stop!

Innodb/XtraDB tables do benefit from being reorganized often. You can get data physically laid out in primary key order as well as get better feel for primary key and index pages and so using less space, it is just OPTIMIZE TABLE might not be best way to do it. If you’re running Innodb Plugin on [...]

Tuning InnoDB Concurrency Tickets

InnoDB has an oft-unused parameter innodb_concurrency_tickets that seems widely misunderstood. From the docs: “The number of threads that can enter InnoDB concurrently is determined by the innodb_thread_concurrency variable. A thread is placed in a queue when it tries to enter InnoDB if the number of threads has already reached the concurrency limit. When a thread [...]

Paul McCullagh answers your questions about PBXT

Following on from our earlier announcement, Paul McCullagh has responded with the answers to your questions – as well as a few I gathered from other Percona folks, and attendees of OpenSQL Camp. Thank you Paul! What’s the “ideal” use case for the PBXT engine, and how does it compare in performance?  When would I [...]

Tokyo Tyrant – The Extras Part I : Is it Durable?

You know how in addition to the main movie you have extras on the DVD.  Extra commentary, bloopers, extra scenes, etc? Well welcome the Tyrant extras.  With my previous blog posts I was trying to set-up a case for looking at NOSQL tools, and not meant to be a decision making tool.  Each solution has [...]

High-Performance Click Analysis with MySQL

We have a lot of customers who do click analysis, site analytics, search engine marketing, online advertising, user behavior analysis, and many similar types of work.  The first thing these have in common is that they’re generally some kind of loggable event. The next characteristic of a lot of these systems (real or planned) is [...]

How to calculate a good InnoDB log file size

Peter wrote a post a while ago about choosing a good InnoDB log file size.  Not to pick on Peter, but the post actually kind of talks about a lot of things and then doesn’t tell you how to choose a good log file size!  So I thought I’d clarify it a little. The basic [...]

How expensive is a WHERE clause in MySQL?

This is a fun question I’ve been wanting to test for some time.  How much overhead does a trivial WHERE clause add to a MySQL query?  To find out, I set my InnoDB buffer pool to 256MB and created a table that’s large enough to test, but small enough to fit wholly in memory:

ANALYZE: MyISAM vs Innodb

Following up on my Previous Post I decided to do little test to see how accurate stats we can get for for Index Stats created by ANALYZE TABLE for MyISAM and Innodb. But before we go into that I wanted to highlight about using ANALYZE TABLE in production as some people seems to be thinking [...]