In the last post choosing about the right type; there is a case about quoting the tuple values; that I forgot to mention which is pretty much a common mistake when string data types are used for storing int or float/double representation (well sometimes you need to use string due to length or to avoid [...]

Today evening one of my friend asked me in the IM to look into one of his production server where a query was taking ~11 seconds to run on 20 million row table, even though the query is using the right index and the plan as shown below:

mysql> explain SELECT channel, COUNT(channel) AS visitors FROM [...]

I have uploaded my three presentations from the 2010 MySQL Users Conference in Santa Clara, California which was my 5th consecutive year appearing as a speaker.

• IGNITION – MySQLCamp for Oracle DBA – Volume I
• LIFTOFF – MySQLCamp for Oracle DBA – Volume 2
• 10x Performance Improvements – A Case Study

A full history of my MySQL presentations can be found on the Presenting page.

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Ever since MySQL 5.5 beta has been announced by Edward Screven, Oracle’s chief corporate architect; there is lot of positive buzz (here, here, …) about the performance and scalability improvements added in this release. We should all be thankful to Michael Ronstrom (as most of the key developers are already working on different forks), who [...]

We all know how important hardware RAID controllers are in today’s data storage performance especially when dealing with large data sets. If we look at the trend from now to couple of years back; they really evolved rapidly with lot of useful features and their usage also grown as most of the new servers [...]

What a busy week! Lots of MySQL 5.5 announcements that just happened to coincide with the MySQL Conference and Expo in Silicon Valley. Here are some highlights of the performance and scalability work that the InnoDB team was involved with.

A good prep for the week of news is the article Introduction to MySQL 5.5, which includes information about the major performance and scalability features. That article will lead you into the MySQL 5.5 manual for general features and the InnoDB 1.1 manual for performance & scalability info.

Then there were the conference presentations from InnoDB team members, which continued the twin themes of performance and scalability:

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At the UC 2010 I will have a session on MySQL Cluster Performance Tuning. This session will address a lot of the most common performance problems I see in my day to day job with Cluster. A small excerpt of the talk is below here and many other things will be addressed in the session (JOINs, schema optimization, batching, indexes, parameter tuning etc). I hope to see you there!

First a bit on ndb_autoincrement_prefetch_sz and then blobs!

ndb_autoincrement_prefetch_sz

One thing is contention on auto_increments, which can really slow down performance.
By default the ndb_autoincrement_prefetch_sz=1. This means that the mysqld will cache one auto_increment number and then go down to the data …

In vBulletin Board System there is session table contains online user information and tracking, in which forum now, what the current URL now, So it is have huge concurrent update statement, By default this table is MEMORY engine because its data not important in case MySQL restart.

I notice early loaded in MySQL and server, So I do full tuning for the server then analyze slow query using

I’ve been wanting to write a backup script for a while now that does the following: reads the partition information for the directory that you are backing up into and computes the used/available/percentage-available space. Then it reads the total data size from the MySQL tables and ensures that you have enough space on disk (for [...]

Last week a customer called me and reported that MySQL was 30 times slower than MS SQL server. Oooops. That's a lot. No way to argue or throw smoke bombs. 30 times slower! It was a standard installation of MySQL (typical install option) on plain Windows 7 and the same for MS SQL Server 2008. The test run was a batch of 30.000 INSERT commands in an SQL script. Runtime was 1 minute on MSSQL and 30 minutes on MySQL. Some tests later we found out that it was only bad on InnoDB. MyISAM was as fast as MSSQL. (I didn't care which one was a bit faster. I didn't care as long as InnoDB was 30 times slower) Finally we nailed the problem down to one parameter in MySQL: innodb_flush_log_at_trx_commit Each INSERT statement is a single transaction (autocommit mode). MySQL is configured very faithfully and ensures that each …