LVM snapshots is one powerful way of taking a consistent backup of your MySQL databases – but did you know that you can now restore directly from a snapshot (and binary logs for point in time recovery) in case of that ‘Oops’ moment? Let me show you quickly how. This howto assumes that you already [...]
How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 4 Comments
In my previous post I explained how it could be possible to recover, on some specific cases, a single table from a full backup in order to save time and make the recovery process more straightforward. Now the scenario is worse because we don’t have a backup or the backup restore process doesn’t work. How [...]
Connecting orphaned .ibd files
May 13, 2011 By 19 Comments
There are two ways InnoDB can organize tablespaces. First is when all data, indexes and system buffers are stored in a single tablespace. This is typicaly one or several ibdata files. A well known innodb_file_per_table option brings the second one. Tables and system areas are split into different files. Usually system tablespace is located in [...]
UDF -vs- MySQL Stored Function
September 6, 2010 By 8 Comments
Few days ago I was working on a case where we needed to modify a lot of data before pushing it to sphinx – MySQL did not have a function to do the thing so I thought I’ll write MySQL Stored Function and we’ll be good to go. It worked! But not so well really [...]
MySQL-Memcached or NOSQL Tokyo Tyrant – part 1
October 15, 2009 By 16 Comments
All to often people force themselves into using a database like MySQL with no thought into whether if its the best solution to there problem. Why? Because their other applications use it, so why not the new application? Over the past couple of months I have been doing a ton of work for clients who [...]
High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
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 Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
Our customers or prospective customers often ask us how we do a performance audit (it’s our most popular service). I thought I should write a blog post that will both answer their question, so I can just reply “read all about it at this URL” and share our methodology with readers a little bit. This [...]
Hacking to make ALTER TABLE online for certain changes
October 29, 2007 By 26 Comments
Suppose you want to remove auto_increment from 100G table. No matter if it’s InnoDB or MyISAM, you’d usually ALTER TABLE huge_table CHANGE id id int(6) NOT NULL and then wait hours for table rebuild to complete. If you’re unlucky i.e. you have a lot of indexes and not too much RAM – you could end [...]
Heikki Tuuri Innodb answers – Part I
October 26, 2007 By 19 Comments
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 [...]
MySQL Users Conference – Innodb
May 9, 2007 By 6 Comments
It might look like it is too late to write about stuff happened at Users Conference but I’m just starting find bits of time from processing accumulated backlog. The Theme of this Users Conference was surely Storage Engines both looking at number of third party storage engine presented, main marketing message – Storage Engine partnership [...]
