If you've ever wished you could see MySQL's EXPLAIN output formatted as a tree, now you can. MySQL Visual Explain transforms EXPLAIN output into a hierarchical view of the query plan, which is significantly easier to read and understand.

I've just released changes to two of the tools in MySQL Toolkit. MySQL Table Checksum got some convenient functionality to help you recursively check slaves for bad replicated checksum chunks. MySQL Archiver got statistics-gathering functionality to help you optimize your archiving and purging jobs, plus a few important bug fixes.

In two blogs I follow, Andy Leonard's blog on SQLBlogs.com and Sheeri Kritzer's The MySQL She-BA, the question of what is a database administrator has come back up. Andy has posted twice on the topic, first with how DBAs are an enterprise requirement and then a follow-up to that post. In Sheeri's case, she was pointing out that a system administrator friend of hers considers the use of phpMyAdmin as a determining factor on whether or not one is DBA: he's not much of a DBA …

This release fixes some bugs and improves the chunking functionality. MySQL Table Checksum had a few minor bugs and one major bug with the chunking functionality. I also rewrote the chunking, though the behavior is backwards compatible. I am very happy with the way it works now, and will probably not make any more incompatible changes to it. The changes enabled me to add support for chunking on float, double and decimal columns.

It still doesn't support chunking on character-based columns, though I know now how I'll do it if I do. Also, support for ENUM and SET shouldn't be hard to add. I have no need for these features myself. If you need it, please file a bug report on the Sourceforge tracker.

MySQL Toolkit distribution 620 updates documentation and test suites, includes some major bug fixes and functionality changes, and adds one new tool to the toolkit. This article is mostly a changelog, with some added notes.

Many of the tools have matured and I just needed to make the documentation top-notch, but there's still a lot to be done on the crucial checksumming and syncing tools. Time is in short supply for me right now, though. In fact, I actually finished this release on June 22, but wasn't able to release it till just tonight!

It's finally here: a single-file download for all the tools in MySQL Toolkit. During this process I also upgraded every package in the toolkit to a new release, combining new versioning and some simple non-functional changes with (mostly minor) changes I'd committed but not yet released. Details are at the end of this post.

This release fixes some minor bugs and adds a plugin mechanism. Now you can extend MySQL Archiver with your own code easily. You could use this to run setup and tear-down, hook code into the archiving process, and more. Possibilities include building summary tables in a data warehouse during archiving, handling dependencies such as foreign keys before archiving each row, or applying advanced logic to determine which rows to archive.

MySQL Archiver is the implementation of the efficient forward-only archiving and purging strategies I wrote about more than a year ago. It nibbles rows from a table, then inserts them into another table and/or writes them to a file. The object is to do this without interfering with critical online transaction-processing (OLTP) queries.

Since starting the innotop and mysqltoolkit projects on Sourceforge, I have learned a lot about how to use source control more effectively -- especially how branching and tagging can be used. Still, I have limited experience. I want to package all the tools in MySQL Toolkit together and release them in one archive, but I don't know the best way to do it; every idea seems to have drawbacks. Read on for the details, and if you have suggestions, would you please leave comments for me?

MySQL Table Checksum 1.1.6 enhances chunking, adds features and fixes bugs. The chunking functionality is where I continue to put most of my effort. This release's behavior is incompatible with the last release, and it will probably change again in the future.

Thanks to everyone who has been helping me chase down bugs, including one user who sent me a major patch! It's a great feeling to get a patch.