Clients often ask what the differences are between the various InnoDB isolation levels, or what ACID means. Here are some simple explanations for those that have not yet read the manual and committed it to memory.

READ UNCOMMITTED
Every select operates without locks so you don’t get consistency and might have dirt reads, which are potentially earlier versions of data. So, no ACID support here.

READ COMMITTED
Has consistent reads without locks. Each consistent read, even within the same transaction, sets and reads its own fresh snapshot.

REPEATABLE READ
The InnoDB default isolation level for ACID compliance. All reads within the same transaction will be consistent between each other – ie, the C in ACID. All writes will be durable, etc etc.

SERIALIZABLE
Same as REPEATABLE READ but MySQL converts regular select …

We’re proud to announce the next release of MySQL Connector/Net version 6.3.4.  This release is GA (Generally Available).

We hope you will make MySQL Connector/Net your preferred set of .NET components including our ADO.Net library and other Microsoft .NET frameworks components such as our Visual Studio plugin and Entity Framework for MySQL.

We are dedicated to providing the best tools for your MySQL database .NET applications.

Special thanks go to all the great MySQL beta testers that provided valuable ideas, insights, and bug reports to the Connector/Net team.  Your beta feedback truly helped us improve the product.

Version 6.3.4 provides the following new features:
- The ability to dynamically enable/disable query analysis at runtime.
- Visual Studio 2010 compatibility
- Improved compatibility with Visual Studio wizards using our new SQL Server mode
- Support for …

I recently started exploring the wonders of mk-table-checksum after spending too long dismissing the magic-like maatkit toolkit. What follows is not an exhaustive treatment of mk-table-checksum, but just an overview and some things I had to learn by trying the tool out.

The basic principle is based on the CHECKSUM TABLE table maintenance statement supported in the MySQL Server. The mk-table-checksum runs a CHECKSUM TABLE command on all (or some) tables. The results of that are stored in another table on the server.

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If you have tested MyQuery 3.3.0 and have problems with a dialog poping up saying that the "application configuration is incorrect", then I am working on this. The reason for this problem is that I now use Visual Stuio 2008 for building, and now Microsoft insists on things such as manifests and stuff. To be frank, insisting on manifests isn't necessarily a bad thing, actually it's pretty cool. The issue is that when there is a problem with them, the messages you get from Windows are, well, less helpful.
In the message you get when you try to run MyQuery probably says nothing about the manifest or anything. In my mind, it should. Also, if you link dynamcically with the Microsoft redistributable DLLs, then you want manifests for those also. Ah well. I am working on it anyway.
I will move to a new VS 2008 generated project, instead of migrating the old as I did before, and build a new distribution. As far as I can see, this will fix these …

I just have to chime in about how happy I am with my new job. I now work for Blue Gecko, as of August 30th. My role is a Senior Database and Systems Administrator. Blue Gecko is based out of Seattle though I'll be working out of my home in New Hampshire, albeit with my frequent travels to Seattle for family reasons, this will work out quite well.

Already in the last week, I've engaged in several tasks, all of which have been very interesting problems to solve. Not only that, but I've spoken with several existing and potential customers and never realized I really enjoy consulting with and acquiring customers-- hearing what problems they need to solve and being able to ascertain quickly how to solve those problems, making the customer look forward to engaging with us.

Who is Blue Gecko?

Based out of Seattle, their website states ( …

I just realized that I didn’t publicize this in the Postgres world, or anywhere but the MySQL blogosphere for that matter. Some folks at my company have released a generic TCP-response-time tool. Very useful for monitoring, benchmarks, historical metrics, and so on. It’s kind of like iostat, but for TCP traffic, and fully focused on time, not traffic size. Performance == time and tasks, and this is a lightweight way to measure that data.

We continue to see more evidence of the themes we discuss in our latest CAOS special report, Seeding the Clouds, which examines the open source software used in cloud computing, the vendors backing open source, the cloud providers using it and the impact on the industry.

First, as usual, we are seeing consistencies between our own research — which indicates open source is a huge part of today’s cloud computing offerings from major providers like Amazon, Google, Rackspace, Terremark and VMware — and that of code analysis and management vendor Black Duck. In its analysis of code that runs the cloud, Black Duck also found a preponderance of open source pieces, in many cases the same projects we profile in our report.

Indeed, open source software is an important part of the infrastructure, …

There are approximately 3 weeks left to submit your MySQL DBA-related presentations to Collaborate 2011, held in Orlando, FL April 10-14. Experience has shown that the best presentations are submitted well in advance of the deadline, so now is a great time to submit while you have plenty of time to create a good abstract.

Information and the link to submit abstracts are at http://collaborate11.ioug.org/. I posted a cheat sheet on how to fill out the Call for Presentations for MySQLers a while ago, and as always feel free to ask me any questions.

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Apparently, Digg performed a big migration from MySQL to Cassandra and a big migration to their new Digg v4 architecture and now their VP of Engineering has been shown the door:

Ever since Digg launched its new site design, it’s been plagued with all kinds of trouble, not least of which is that it keeps going down. The problems with the new architecture are so bad that VP of Engineering John Quinn is now gone, we’ve confirmed with sources close to Digg.

In a Diggnation video today, CEO Kevin Rose explained some of the technical issues the site is dealing with and why it can’t simply roll back to the previous architecture. The new version of Digg, v4, is based on a distributed database called Cassandra, which replaced the MySQL database the site ran on before. Cassandra is very advanced—it is supposed to be faster and scale …

If you are coming to this year’s Oracle OpenWorld 2010, please do visit us at Booth #3824.

We will have our backup solution experts at the show to discuss any of your database or infrastructure backup needs.

When it comes to backing up various products offered by Oracle, we have several solutions:

• Amanda Enterprise: Backup solution for Oracle Enterprise Linux and Solaris based systems.
• Zmanda Oracle Agent: Backs up live Oracle databases to Amanda backup server - which can store backup archives on disks, tapes, or storage clouds.
• Zmanda Cloud Backup: Backs …