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 [...]
Is your MySQL buffer pool warm? Make it sweat!
April 16, 2013 By 6 Comments
Today’s blog post diving into the waters of the MySQL buffer pool is a cross-post from Groupon’s engineering blog, and is Part 1 of 2. Thank you to Kyle Oppenheim at Groupon for contributing to this project and post. We’ll be posting Part 2 on Thursday. I’ll be at the Percona Live MySQL Conference and [...]
Fun with the MySQL pager command
January 21, 2013 By 6 Comments
Last time I wrote about a few tips that can make you more efficient when using the command line on Unix. Today I want to focus more on pager. The most common usage of pager is to set it to a Unix pager such as less. It can be very useful to view the result [...]
Measuring the amount of writes in InnoDB redo logs
October 8, 2012 By 4 Comments
Choosing a good InnoDB log file size is key to InnoDB write performance. This can be done by measuring the amount of writes in the redo logs. You can find a detailed explanation in this post. To sum up, here are the main points: The redo logs should be large enough to store at most [...]
How expensive is USER_STATISTICS?
June 2, 2012 By 14 Comments
One of our customers asked me whether it’s safe to enable the so-called USER_STATISTICS features of Percona Server in a heavy-use production server with many tens of thousands of tables. If you’re not familiar with this feature, it creates some new INFORMATION_SCHEMA tables that add counters for activity on users, hosts, tables, indexes, and more. [...]
ext4 vs xfs on SSD
March 15, 2012 By 26 Comments
As ext4 is a standard de facto filesystem for many modern Linux system, I am getting a lot of question if this is good for SSD, or something else (i.e. xfs) should be used. Traditionally our recommendation is xfs, and it comes to known problem in ext3, where IO gets serialized per i_node in O_DIRECT [...]
Dynamic row format for MEMORY tables
September 6, 2011 By 5 Comments
The latest Percona Server release has one new feature: now MEMORY tables can have BLOB and TEXT columns, and VARCHAR columns will not waste space due to implicit extension to CHAR.
Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
Shard-Query is an open source tool kit which helps improve the performance of queries against a MySQL database by distributing the work over multiple machines and/or multiple cores. This is similar to the divide and conquer approach that Hive takes in combination with Hadoop. Shard-Query applies a clever approach to parallelism which allows it to [...]
Innodb row size limitation
April 7, 2011 By 12 Comments
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.
Shard-Query adds parallelism to queries
November 15, 2010 By 18 Comments
Preamble: On performance, workload and scalability: MySQL has always been focused on OLTP workloads. In fact, both Percona Server and MySQL 5.5.7rc have numerous performance improvements which benefit workloads that have high concurrency. Typical OLTP workloads feature numerous clients (perhaps hundreds or thousands) each reading and writing small chunks of data. The recent improvements to [...]
