This blog post is part two in what is now a continuing series on the Star Schema Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using only the InnoDB storage engine. In my testing I discovered that innodb_old_blocks_time had an effect on performance of the benchmark. There was [...]
Replication in MySQL 5.6: GTIDs benefits and limitations – Part 1
May 21, 2013 By 3 Comments
Global Transactions Identifiers are one of the new features regarding replication in MySQL 5.6. They open up a lot of opportunities to make the life of DBAs much easier when having to maintain servers under a specific replication topology. However you should keep in mind some limitations of the current implementation. This post is the [...]
More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
Since my first post on MySQL transaction descriptors optimization introduced in Percona Server 5.5.30-30.2 and a followup by Dimitri Kravchuk, we have received a large number of questions on why the benchmark results in both posts look rather different. We were curious as well, so we tried to answer that question by retrying benchmarks on [...]
trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 2 Comments
One major problem in terms of MySQL performance that still stands in the way of InnoDB scalability is the trx_list scan on consistent read view creation. It was originally reported as a part of MySQL bug #49169 and can be described as follows. Whenever a connection wants to create a consistent read, it has to [...]
Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
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! [...]
Percona Toolkit for MySQL Webinar Followup Questions
April 5, 2013 By 1 Comment
I didn’t have time to answer all of the questions during Wednesday’s MySQL webinar, “5 Percona Toolkit Tools That Could Save Your Day,” but as promised, here are all of the questions and my answers. (A recording is available here.) Q: One of the links to download the Percona Toolkit for MySQL (percona.com/get/percona-toolkit.tgz) doesn’t work! A: [...]
MySQL 5.6.10 Optimizer Limitations: Index Condition Pushdown
March 14, 2013 By 2 Comments
While preparing the webinar I will deliver this Friday, I ran into a quite interesting (although not very impacting) optimizer issue: a “SELECT *” taking half the time to execute than the same “SELECT one_indexed_column” query in MySQL 5.6.10. This turned into a really nice exercise for checking the performance and inner workings of one [...]
How does MySQL Replication really work?
January 9, 2013 By 9 Comments
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 [...]
Speaking at Percona Live London 2012: Choosing Hardware for MySQL
November 19, 2012 By 4 Comments
Another Percona Live event is coming up, this time in London on the 3rd and 4th of December. I’m sure it is going to be as awesome as it was last year. This year, I will talk about ‘Choosing Hardware For MySQL‘. Of course, the most important hardware components will be covered: CPU, Memory, Network, [...]
Percona XtraDB Cluster – installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
Thanks for all, who attended my webinar, I got many questions and I wanted to take this opportunity to answer them. Q: Even ntp has a delay of 0.3-0.4 between servers does that mean a 0.25 as from logs can be an issue ? A: My demo vms were running for a few hours before [...]
