September 17, 2014

Database problems in MySQL/PHP Applications

Article about database design problems is being discussed by Kristian. Both article itself and responce cause mixed feellings so I decided it is worth commenting: 1. Using mysql_* functions directly This is probably bad but I do not like solutions proposed by original article ether. PEAR is slow as well as other complex conectors. I […]

Write contentions on the query cache

While doing a performance audit for a customer a few weeks ago, I tried to improve the response time of their top slow query according to pt-query-digest‘s report. This query was run very frequently and had very unstable performance: during the time data was collected, response time varied from 50µs to 1s. When I ran […]

Sell-an-Elephant-to-your-Boss-HOWTO

Spoiler alert: If your boss does not need an elephant, he is definitely NOT going to buy one from you. If he will, he will regret it and eventually you will too. I must appologize to the reader who was expecting to find an advice on selling useless goods to his boss. While I do […]

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 […]

Caching could be the last thing you want to do

I recently had a run-in with a very popular PHP ecommerce package which makes me want to voice a recurring mistake I see in how many web applications are architected. What is that mistake? The ecommerce package I was working with depended on caching.  Out of the box it couldn’t serve 10 pages/second unless I […]

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 […]

Community Events February-March

February and March as busy months for Community events.  There’s MySQL University, Fosdem, the Seattle MySQL Meetup & Confoo.ca.

Percona is hiring a consultant

We’re hiring. We are looking for the following qualifications: Expert knowledge of MySQL. Not just “certified” — years of production experience with it. You need to know server internals, for example. You need to be able to do anything from optimizing difficult queries to moving high-volume services between data centers without interruption. Expert knowledge of […]

What do we optimize with mk-query-digest ?

When we’re looking at mk-query-digest report we typically look at the Queries causing the most impact (sum of the query execution times) as well as queries having some longest samples. Why are we looking at these ? Queries with highest Impact are important because looking at these queries and optimizing them typically helps to improve […]

A few administrative updates

I wanted to write a few administrative updates in one so I didn’t spam everyone’s feed readers too much. Here we go: We’ve had reports of some lost comments.  We reported this via Twitter a while ago, but thought it was fixed.  We’ll try and pay more attention to spam filtering, but we wanted to […]