May 23, 2013

Benchmarking Percona Server TokuDB vs InnoDB

May 7, 2013 By 32 Comments

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 [...]

Filed Under: Benchmarks, MySQL, Percona Server Tagged With: , , ,

How to recover table structure from InnoDB dictionary

April 22, 2013 By 4 Comments

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 [...]

Filed Under: Insight for DBAs, MySQL Tagged With: , , , , , ,

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. [...]

Filed Under: MySQL Tagged With: , , , , ,

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

March 4, 2013 By 7 Comments

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 [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

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

February 26, 2013 By 1 Comment

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 [...]

Filed Under: Insight for DBAs, Insight for Developers, MySQL Tagged With: , , , , ,

Sphinx search performance optimization: attribute-based filters

January 15, 2013 By 9 Comments

One of the most common causes of a poor Sphinx search performance I find our customers face is misuse of search filters. In this article I will cover how Sphinx attributes (which are normally used for filtering) work, when they are a good idea to use and what to do when they are not, but [...]

Filed Under: Insight for Developers, MySQL Tagged With: , ,

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 [...]

Filed Under: Insight for DBAs, MySQL Tagged With: , ,

On Character Sets and Disappearing Tables

June 21, 2012 By 1 Comment

The MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS=0″ before making schema changes, InnoDB will not allow a column referenced by a foreign key constraint to be modified in such a way that the foreign key will reference a column with a mismatched data type. For instance, if we [...]

Filed Under: Insight for DBAs, MySQL

InnoDB’s gap locks

March 27, 2012 By 15 Comments

One of the most important features of InnoDB is the row level locking. This feature provides better concurrency under heavy write load but needs additional precautions to avoid phantom reads and to get a consistent Statement based replication. To accomplish that, row level locking databases also acquire gap locks. What is a Phantom Read A [...]

Filed Under: MySQL

Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact

March 12, 2012 By 12 Comments

I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition Pushdown (ICP). Its available [...]

Filed Under: Benchmarks, Insight for DBAs, MySQL Tagged With: , , , , , , ,
« Older Posts