To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from [...]
The write cache: Swap insanity tome III
Swapping has always been something bad for MySQL performance but it is even more important for HA systems. It is so important to avoid swapping with HA that NDB cluster basically forbids calling malloc after the startup phase and hence its rather complex configuration. Probably most readers of this blog know (or should know) about [...]
Disconnecting a replication slave is easier with MySQL 5.5+ (RESET SLAVE vs. RESET SLAVE ALL)
It’s not uncommon to promote a server from slave to master. One of the key things to protect your data integrity is to make sure that the promoted slave is permanently disconnected from its old master. If not, it may get writes from the old master, which can cause all kinds of data corruption. MySQL [...]
10 years of MySQL User Conferences
In preparing for this month’s Percona Live MySQL Conference and Expo, I’ve been reminiscing about the annual MySQL User Conference’s history – the 9 times it previously took place in its various reincarnations – and there are a lot of good things, fun things to remember. 2003 was the year that marked the first MySQL user conference [...]
Understanding the maximum number of columns in a MySQL table
This post was initially going to be two sets of polls: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on, ponder those questions and come up with your own answers… and see if you’re right or can prove me wrong! [...]
My Sessions at Percona Live MySQL Conference and Expo 2013
As is typical at the beginning of every April, many of us who submitted talks to the Percona Live MySQL Conference and Expo are wondering why we submitted so many. I had 3 official talks selected, including one that is a 6-hour tutorial, as well as a BoF. Here’s the highlights: Percona XtraDB Cluster / [...]
MySQL 5.6 Compatible Percona Toolkit 2.2 Released
A new Percona Toolkit series has been released: Percona Toolkit 2.2 for MySQL 5.6. Several months in the making and many new features, changes, and improvements make this a great new series. It replaces the 2.1 series for which we plan to do only one more bug fix release (as 2.1.10) then retire. 2.2 is [...]
Percona Live MySQL Conference and Expo 2013: It feels like 2007 again
I actually don’t remember exactly whether it was in 2006, 2007 or 2008 — but around that time the MySQL community had one of the greatest MySQL conferences put on by O’Reilly and MySQL. It was a good, stable, predictable time. Shortly thereafter, the MySQL world saw acquisitions, forks, times of uncertainly, more acquisitions, more forks, [...]
Testing the Virident FlashMAX II
Approximately 11 months ago, Vadim reported some test results from the Virident FlashMax 1400M, an MLC PCIe SSD device. Since that time, Virident has released the FlashMAX II, which promises both increased capacity and increased performance over the previous model. In this post, we present some benchmark results comparing this new model to its predecessor, [...]

