After compiling Percona Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested in testing – it is an insert-intensive workload (which is TokuDB’s strong suit) with some roll-up aggregation, which should produce updates in-place (I will use INSERT .. ON DUPLICATE KEY UPDATE statements [...]
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 [...]
Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL now available
April 17, 2013 By 2 Comments
Percona is glad to announce the release of Percona XtraDB Cluster 5.5.30-23.7.4 for MySQL on April 17, 2013. Binaries are available from the downloads area or from our software repositories. New Features: Percona XtraDB Cluster has implemented initial implementation of weighted quorum. Weight for node can be assigned via pc.weight option in the wsrep_provider_options variable. [...]
MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
So far most of the benchmarks posted about MySQL 5.6 use the sysbench OLTP workload. I wanted to test a set of queries which, unlike sysbench, utilize joins. I also wanted an easily reproducible set of data which is more rich than the simple sysbench table. The Star Schema Benchmark (SSB) seems ideal for this. [...]
Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
February 25, 2013 By 10 Comments
There are many reasons for wanting a small MySQL database server: You’re a uni student who wants to learn the SQL language better and needs a mini-testbox You’re a Windows user who wants to play around with Percona Server on Linux You’re a corporate application developer who wants a small SQL development & test box [...]
MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
Preparing for my talk for Percona MySQL University in Raleigh,NC, Tuesday 29th of January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give a feel for how massive work have been done for this release in variety of areas. I’m sure the list is not [...]
Edge-case behavior of INSERT…ODKU
October 27, 2012 By 6 Comments
A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really, the majority of the database was a single table with [...]
When is MIN(DATE) != MIN(DATE) ?
September 4, 2012 By 5 Comments
Inspiration for this post is courtesy of a friend and former colleague of mine, Greg Youngblood, who pinged me last week with an interesting MySQL puzzle. He was running Percona Server 5.5.21 with a table structure that looks something like this:
1 2 3 4 5 6 7 8 9 | CREATE TABLE foo ( id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, uid INT UNSIGNED NOT NULL, update_time DATETIME NOT NULL, .... INDEX `uid` (uid, update_time), INDEX `bar` (some_other_columns) .... ) ENGINE=InnoDB; |
When he ran this query:
1 | SELECT MIN(update_time) FROM foo WHERE update_time IS NOT NULL AND update_time <> '0000-00-00 00:00:00'; |
The result came back as 2012-06-22 10:28:16. [...]
Visualization tools for pt-query-digest tables
August 31, 2012 By 6 Comments
When you process MySQL slow query logs using pt-query-digest you can store samples of each query into query_review table and historical values for review trend analysis into query_review_history table. But it could be difficult to easily browse those tables without a good GUI tool. For the visual browsing of tables created by pt-query-digest you may [...]
Differences between READ-COMMITTED and REPEATABLE-READ transaction isolation levels
August 28, 2012 By 3 Comments
As an instructor with Percona I’m sometimes asked about the differences between the READ COMMITTED and REPEATABLE READ transaction isolation levels. There are a few differences between READ-COMMITTED and REPEATABLE-READ, and they are all related to locking.
