May 19, 2013

Feature preview: Compact backups in Percona XtraBackup

We continue to improve Percona XtraBackup, and today I would like to give a preview for one feature which comes in next Percona XtraBackup 2.1 release. This feature is “Compact backups”, and let me explain what it does. As you may know InnoDB PK (Primary Key) contains all data, and all secondary indexes are only [...]

Read/Write Splitting with PHP Webinar Questions Followup

Today I gave a presentation on “Read/Write Splitting with PHP” for Percona Webinars.  If you missed it, you can still register to view the recording and my slides. Thanks to everyone who attended, and especially to folks who asked the great questions.  I answered as many as I could during the session, but here are [...]

Sphinx search performance optimization: attribute-based filters

One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do when they are not, but [...]

How does MySQL Replication really work?

While we do have many blog posts on replication on our blog, such as on replication being single-threaded, on semi-synchronous replication or on estimating replication capacity, I don’t think we have one that covers the very basics of how MySQL replication really works on the high level. Or it’s been so long ago I can’t [...]

Quickly finding unused indexes (and estimating their size)

I had a customer recently who needed to reduce their database size on disk quickly without a lot of messy schema redesign and application recoding.  They didn’t want to drop any actual data, and their index usage was fairly high, so we decided to look for unused indexes that could be removed. Collecting data It’s [...]

Full table scan vs full index scan performance

Earlier this week, Cédric blogged about how easy we can get confused between a covering index and a full index scan in the EXPLAIN output. While a covering index (seen with EXPLAIN as Extra: Using index) is a very interesting performance optimization, a full index scan (type: index) is according to the documentation the 2nd [...]

Get Me Some Query Logs!

One of my favorite tools in the Percona Toolkit is pt-query-digest.  This tool is indispensable for identifying your top SQL queries, and analyzing which queries are accounting for your database load. But the report you get from pt-query-digest is only as good as the log of queries you give it as input.  You need a large [...]

Speaking at Percona Live London 2012: Percona XtraDB Cluster in a nutshell

If you are interested by a great and revolutionary HA solution for MySQL or even if you already have some experience with PXC and/or Galera, I invite you to attend the tutorial I will deliver in Percona Live MySQL Conference London 2012 (PLUK2012), December 3rd : Percona XtraDB Cluster in a nutshell. Small amount of [...]

Question of the week: Maximum number of tables per MySQL instance.

I’ve got the great response to my two previous polls (1,2) so lets continue learning about how we all use MySQL. The question of this week is What is the maximum number of tables per MySQL instance do you use ? Thank you for participating!

What is the largest amount of data do you store in MySQL ?

My previous poll got a great response so I thought I should continue these series. The question of the day today is How much data do your store in your largest MySQL instance ? I’m interested about single instance not the total amount of data you have in MySQL in your Sharded replicated environment. Feel [...]