To benchmark IO on Linux and MySQL transaction processing, SysBench is a popular choice that can do both. After poking around at the source code, it seems PostgreSQL and Oracle are also included for transaction processing testing if you have the proper header files, but I didn’t test those.

To benchmark IO on Windows and SQL Server transaction processing, Microsoft provides two tools, SQLIO and SQLIOSim. SQLIO is a misnomer in that it really doesn’t have much to do with SQL Server. It is a general purpose disk IO benchmark tool.

So today I was playing with SysBench and noticed that I can compile and build it on Windows as well. I decided I should run IO benchmark on a single machine with both tools (SQLIO and SysBench), and see if I could reconcile the results.

To make things simple, I thought I would just benchmark random read of 3G (orders of magnitude bigger than disk controller cache) files for 5 minutes (300 …

Here’s a little trivia that you might find helpful. Suppose that I have the following in the MySQL slow query log (abbreviated for clarity):

# User@Host: root[root] @ localhost [127.0.0.1]
# Time: 100919 17:58:52
# Query_time: 9.648427  Lock_time: 8.648039
select sleep(1) from t limit 1;

To get this into the slow query log, I set the long_query_time to 0 and opened two sessions. In one session I ran LOCK TABLES t WRITE, and in the other I tried to select from that table. As you can see above, 1) LOCK TABLES contributes to the Lock_time number, and 2) the Query_time is the sum of execution time and lock time.

Now, I’ll set long_query_time = 2 and run the same test. What happens? Nothing shows up in the slow query log, because 3) the time spent waiting for table locks doesn’t count towards the slow query time threshold.

A final note: …

Relational Database Index Design and the Optimizers

Relational Database Index Design and the Optimizers. By Tapio Lahdenmaki and Mike Leach, Wiley 2005. (Here’s a link to the publisher’s site).

I picked this book up on the advice of an Oracle expert, and after one of my colleagues had read it and mentioned it to me. The focus is on how to design indexes that will produce the best performance for various types of queries. It goes into quite a bit of detail on how databases execute specific types of queries, including sort-merge joins and multiple index access, and develops a generic cost model that can be used to produce a quick upper-bound estimate (QUBE) for the …

Mondrian supports a large number of back-end databases. So many in fact, that we rely on contributors to add the support, and we have tried to standardize the steps to support a new database.

I thought it might be worthwhile to reiterate those steps. The steps are:

1. Write a dialect class. The dialect must implement the Dialect interface, and will probably be a subclass of JdbcDialectImpl. The only prerequisites are that your database has a JDBC driver and supports SQL-92: SELECT .. FROM .. JOIN .. GROUP BY. Mondrian will glean as much information as it can, such as how your database quotes identifiers that contain mixed-case or spaces, from the JDBC driver. But you will need to override methods to provide information that the …

Team OSSCube could not feel prouder than what we felt at the sight of the thorngs and hordes assembled right on time for registrations to start. So much so that in the initial enthusiasm to register and participate at the conference, all FOSS evangelists created huge queues and pools near the registration desk. The patience and the enthusiasm shared by the community was immense (We love you!). The conference started with a slight delay of the schedule as the team channelised the masses inside the halls and prepared the show for the inauguration.

The Minister-in-Charge, Department of IT (Govt of West Bengal) - Dr. Debesh Das, inaugrated the conference with a speech on the FOSS scenario in India and the relevance of open source to all its stakeholders and how new inroads are eing made by the community …

Team OSSCube could not feel prouder than what we felt at the sight of the thorngs and hordes assembled right on time for registrations to start. So much so that in the initial enthusiasm to register and participate at the conference, all FOSS evangelists created huge queues and pools near the registration desk. The patience and the enthusiasm shared by the community was immense (We love you!). The conference started with a slight delay of the schedule as the team channelised the masses inside the halls and prepared the show for the inauguration.

The Minister-in-Charge, Department of IT (Govt of West Bengal) - Dr. Debesh Das, inaugrated the conference with a speech on the FOSS scenario in India and the relevance of open source to all its stakeholders and how new inroads are eing made by the …

We’re proud to announce the next release of MySQL Workbench, version 5.2.28. This maintenance release features improvements to the Workbench scripting Shell as well as various fixes.

Enhancements to the Workbench 5.2.28 Scripting Shell makes development and usage of Workbench Scripts and Plug-ins easier by

• Providing a new workbench shell scripting file browser
• Allowing users to more easily create/edit/save/execute Workbench python and lua scripts
• Including Handy Workbench “Scripting” snippets that can easily be executed or copied.
• Adding a new script results output panel

For more on Workbench Scripting and Plug-in development see

http://wb.mysql.com/?page_id=664

As always, we want to thank everyone for the great feedback we have received. This helps us to continuously improve and extend …

Since 5.5 is announced as Release Candidate now, I'll not compare it with 5.1 anymore - I think there was written enough about the performance gain even since introduction of 5.4 :-)

From the other side, we want to be sure that the final 5.5 will be at least as good as 5.5.4 release, and here the feedback from real users with real workloads will be very precious! So, please, don't keep quiet! :-))

After that, few notes while testing MySQL 5.5 on dbSTRESS and points for discussions..

Buffer Pool and Purge

Last month I've got some time to focus on the Buffer Pool pages management I've observed many months before with older MySQL/InnoDB versions, and now was curious if I'll reproduce the same issue with MySQL 5.5.4 too...

Few words about the tested workload:

• still dbSTRESS ;-)
• but "light" scenario which may be very common for many web servers: there are only SELECT and …

MySQL has a well-earned reputation for being easy-to-use and delivering performance and scalability. In previous versions, MyISAM was the default storage engine. In our experience, most users never changed the default settings. With MySQL 5.5, InnoDB becomes the default storage engine. Again, we expect most users will not change the default settings. But, because of InnoDB, the default settings deliver the benefits users expect from their RDBMS — ACID Transactions, Referential Integrity, and Crash Recovery. Lets explore how using InnoDB tables improves your life as a MySQL user, DBA, or developer.

Background

In the first years of MySQL growth, early web-based applications didn’t push the limits of concurrency and availability. In 2010, hard drive and memory capacity and the performance/price ratio have all gone through the roof. Users pushing the performance boundaries of MySQL care a lot about reliability and …

At MySQL, we know our users want Performance, Scalability, Reliability, and Availability, regardless of the platform the choose to deploy. We have always had excellent benchmarks on Linux, and with MySQL 5.5, we are also working hard on improving performance on Windows.

The original patch of improving Windows performance was developed by MySQL senior developer Vladislav Vaintroub; benchmarks by QA engineer Jonathan Miller. We integrated the patch into MySQL 5.5 release.

The following two charts show the comparison of MySQL 5.5 vs. MySQL 5.1 (plugin) vs. MySQL 5.1 (builtin) using sysbench:

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