The latest from the MySQL community

I found myself thinking this evening about how someone could set about writing aggregate functions using Perl and on an idle Google search, came across this webpage entitled User-defined Aggregate Functions in DB2 Universal Database.I wondered if a similar technique could be applied for our implementation of External Language Stored Procedures for MySQL. It turns out that the answer is:

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This release contains minor bug fixes and new features. Besides the little bug fixes, there's a fun new feature in mk-heartbeat: it can auto-discover slaves recursively, and show the replication delay on all of them, to wit:

baron@keywest ~ $ mk-heartbeat --check --host master -D rkdb --recurse 10
master 0
slave1 1
slave2 1
slave3 4

(Not actual results. Your mileage may vary. Closed course, professional driver. Do not attempt).

Nothing else in this release is very exciting. I just wanted to get the bug fixes out there.

This release contains bug fixes and new features. It also contains a new tool: my implementation of Paul Tuckfield's relay log pipelining idea. I have had quite a few responses to that blog post, and requests for the code. So I'm releasing it as part of Maatkit.

I dashed off a hasty post about speeding up replication slaves, and gave no references or explanation. That's what happens when I write quickly! This post explains what the heck I was talking about.

Paul Tuckfield of YouTube has spoken about how he sped up his slaves by pre-fetching the slave's relay logs. I wrote an implementation of this, tried it on my workload, and it didn't speed them up. (I didn't expect it to; I don't have the right workload). I had a few email exchanges with Paul and some other experts on the topic and we agreed my workload isn't going to benefit from the pre-fetching.

In the meantime, I've got a pretty sophisticated implementation of Paul's idea just sitting around, unused. I haven't released it for the same reasons Paul didn't release his: I'm afraid it might do more harm than good.

However, if you'd like the code, send me an email at [baron at this domain] and I'll share the code with you. In return, I would like you to tell me about your hardware and your workload, and to do at least some rudimentary benchmarks to show whether it works or not on your workload. If I find that this is beneficial for …

This release contains bug fixes and new features. Click through to the full article for the details. I'll also write more about the changes in a separate article.

My posts lately have been mostly progress reports and release notices. That's because we're in the home stretch on the book, and I don't have much spare time. However, a lot has also been changing with Maatkit, and I wanted to take some time to write about it properly.

This release contains bug fixes and new features. The biggest new feature, in my opinion, is a new sync algorithm for mk-table-sync. Now you can sync any table with an index more efficiently than previously. This is the return of the speed I promised earlier. (Though I haven't yet benchmarked it; I am very short on time these days. Your benchmarks and other contributions are welcome).

I'm finally feeling like the table sync tool is getting in good shape!

Changelog etc is in the full article.

2007 is almost over and what a year this has been for Wave2!

My programming preferences have gone full circle, from beginning the year playing snakes and ladders (Python), I spent the summer drinking coffee (Java) and finally settled down surrounded by Camel’s, Lama’s and Parrots (Perl). Bizarre but never dull!

Steady progress has been made all round and as always the Open Source community has proven a valuable resource. Not a day went by where I did not discover something new or think of a new idea that could be built using Open Source Software. I only wish I had more time in the day!.

My Christmas present came early this year in the form of a MySQL 5.1 Cluster DBA Certification Study Guide. I have been putting off the final MySQL certification while waiting for the book to arrive, and now it is in my hands the only thing preventing me from taking the …

This release fixes a few bugs, adds minor features, and adds some debugging support to shared code. I'm working on the Nibble sync algorithm for mk-table-sync, and someone has found a few more bugs with mk-parallel-dump, but those might take me a while to complete.