I recently worked on a customer case where at seemingly random times, inserts would fail with Innodb error 139. This is a rather simple problem, but due to it’s nature, it may only affect you after you already have a system running in production for a while.
The Doom of Multiple Storage Engines
One of the big “Selling Points” of MySQL is support for Multiple Storage engines, and from the glance view it is indeed great to provide users with same top level SQL interface allowing them to store their data many different way. As nice as it sounds the in theory this benefit comes at very significant [...]
Why you should ignore MySQL’s key cache hit ratio
I have not caused a fist fight in a while, so it’s time to take off the gloves. I claim that somewhere around of 99% of advice about tuning MySQL’s key cache hit ratio is wrong, even when you hear it from experts. There are two major problems with the key buffer hit ratio, and [...]
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 [...]
Finding your MySQL High-Availability solution – Replication
In the last 2 blog posts about High Availability for MySQL we have introduced definitions and provided a list of ( questions that you need to ask yourself before choosing a HA solution. In this new post, we will cover what is the most popular HA solution for MySQL, replication.
Finding your MySQL High-Availability solution – The questions
After having reviewed the definition my the previous post (The definitions), the next step is to respond to some questions. Do you need MySQL High-Availability? That question is quite obvious but some times, it is skipped. It can also be formulated “What is the downtime cost of the service?”. In the cost, you need to [...]
How much memory can MySQL use in the worst case?
I vaguely recall a couple of blog posts recently asking something like “what’s the formula to compute mysqld’s worst-case maximum memory usage?” Various formulas are in wide use, but none of them is fully correct. Here’s why: you can’t write an equation for it.
Announcing Percona XtraDB Storage Engine: a Drop-in Replacement for Standard InnoDB
Today we officially announce our new storage engine, “Percona XtraDB“, which is based on the InnoDB storage engine. It’s 100% backwards-compatible with standard InnoDB, so you can use it as a drop-in replacement in your current environment. It is designed to scale better on modern hardware, and includes a variety of other features useful in [...]
7 Reasons why MySQL Quality will never be the same
I had a call with Monty the other day and I told him why I think MySQL Server Quality will never be the same again. I’ve been thinking a bit more about it and here is the extended list. In particular I think MySQL Server will never be able to reach its original quality guidelines [...]
Choosing innodb_buffer_pool_size
My last post about Innodb Performance Optimization got a lot of comments choosing proper innodb_buffer_pool_size and indeed I oversimplified things a bit too much, so let me write a bit better description. Innodb Buffer Pool is by far the most important option for Innodb Performance and it must be set correctly. I’ve seen a lot [...]

