May 18, 2013

Virident vCache vs. FlashCache: Part 2

This is the second part in a two-part series comparing Virident’s vCache to FlashCache. The first part was focused on usability and feature comparison; in this post, we’ll look at some sysbench test results. Disclosure: The research and testing conducted for this post were sponsored by Virident. First, some background information. All tests were conducted [...]

Galera Flow Control in Percona XtraDB Cluster for MySQL

Last week at Percona Live, I delivered a six-hour tutorial about Percona XtraDB Cluster (PXC) for MySQL.  I actually had more material than I covered (by design), but one thing I regret we didn’t cover was Flow control.  So, I thought I’d write a post covering flow control because it is important to understand. What [...]

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! [...]

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 [...]

Oracle Technical Experts at the Percona Live MySQL Conference and Expo

I’m pleased to announce that Oracle is sending some of their top technical people to speak at the Percona Live MySQL Conference and Expo. The conference takes place April 22-25, 2013 at the Santa Clara Convention Center and Hyatt Santa Clara. Tomas Ulin, VP, MySQL Engineering for Oracle, will present an invited keynote talk on [...]

InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

This is part 2 in a 3 part series. In part 1, we took a quick look at some initial configuration of InnoDB full-text search and discovered a little bit of quirky behavior; here, we are going to run some queries and compare the result sets. Our hope is that the one of two things [...]

InnoDB Full-text Search in MySQL 5.6 (part 1)

I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many [...]

Can’t Create Thread: Errno 11 (A Tale of Two Ulimits)

Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:

The canonical solution to this issue, if you do a bit of Googling, is to increase the number of processes / threads available to the MySQL user, typically by adding a [...]

The Optimization That (Often) Isn’t: Index Merge Intersection

Prior to version 5.0, MySQL could only use one index per table in a given query without any exceptions; folks that didn’t understand this limitation would often have tables with lots of single-column indexes on columns which commonly appeared in their WHERE clauses, and they’d wonder why the EXPLAIN plan for a given SELECT would [...]

Realtime stats to pay attention to in Percona XtraDB Cluster and Galera

I learn more and more about Galera every day.  As I learn more, I try to keep my myq_gadgets toolkit up to date with what I consider is important to keep any eye on on a PXC node.  In that spirit, I just today pushed some changes to the ‘wsrep’ report, and I thought I’d go over [...]