I recently filed Bug #37359 filesort can be more efficient based on some performance work with an industry standard benchmark. Read on if the internals of how MySQL implements filesort interests you.

Filesort, as the name implies, is used to sort records when there is an ORDER BY clause in the query. The reason it has the prefix "file" is because temporary files may be used to store intermediate results. filesort() uses a per thread sort buffer of size sort_buffer_size to sort the table. filesort() is implemented in sql/filesort.cc.

filesort may not know how many records need to be sorted. It asks the storage engine for an estimate of the number of records in the table via estimate_rows_upper_bound(). If the number of records that fit in the sort buffer is less than the estimate, filesort will use temporary files to store intermediate results. The flow …

A new edition of the MySQL 5.1 Cluster Certification Study Guide is due out any day now. As soon as I get the new on the availability, you will see it here. It will be bigger, better, and all the marking adjectives you would ever want.

But the original, first printing is sold out.

MySQL community, mark your calendars!. On July 8th, 2008, there is a Webinar on Designing scalable architectures with MySQL Proxy.
This is not the usual marketing sponsored webinar. Although we love to show off, this is not a "look-how-good-we-are" presentation. This is a community driven event, where a community member, using only MySQL Proxy and some creativity, solved his production problems.

This is a real story of a community member who used open source software to build a customized scalable architecture to suit his purposes. Isn't it a good story?
I won't steal his thunder and tell you in advance what was the problem about. I will introduce the general concepts about Proxy, and then our guest John Loehrer will tell hist …

krow's post on prepared statements inspired me to write an update on what is getting fixed there.

First, a fix for Bug#27430 is in 5.1 tree.
Overall, this makes prepared statements significantly more stable. I know of only two crashes left ;) -- one is when you run out of memory, which is a design gotcha. The other is Bug#32124. Speaking of this last one, we now have stupid rules saying that if a bug doesn't affect too many people, even if it's a crash, it's not that important. This is a difficult bug, and the rules give an excuse to keep it unfixed.
The few important "feature" bugs that remain are …

While working hard on the MySQL Workbench 5.1 source branch (Linux / OS X versions) we have not forgotten about the 5.0 branch and have fixed another series of bugs - now announcing the release of MySQL Workbench 5.0.23. Workbench now stores and recovers common Application settings - this is one of 26 bugs we corrected for this release. Fetch the latest version and let Workbench deal with your databases.

JFYI: today I migrated the mylvmbackup source tree from my local Subversion repository on http://www.lenzg.org/ to a Bazaar repository on Launchpad.net.

This will hopefully make it easier for contributors to work on the code and share their modifications with others, removing me as the bottleneck for applying and testing patches for new releases. I chose Bazaar primarily because I wanted to get some more hands-on practice with it, now that the MySQL Server source trees have been transferred to it as well (see Kaj's announcement for …

If there’s one thing that bothers me about using a ready-made solution like wordpress for my blog, it’s plug-ins. I hate software plug-ins. The first question every support engineer for any software product that supports plugins asks in response to a trouble report is “are you using any plugins?” And when you say “yep, I’m using plugins!” the reply from support is to disable them immediately and see if the trouble goes away. That’s a problem.

What’s worse, if the plugins are maintained by a third party (often the case), there’s no telling whether or not they’ll exist when the next version of the base software is released, or whether they’ll be supported in future versions of the software.

Two examples that touch my daily life are Firefox, and …

Server-side Prepared Statements are an outdated technology from ancient times, are they? Brian gives a long list of arguments in his blog posting “Prepared Statements, Musings” why one should think twice before using server-side prepared statements. PDO does enforce the use of prepared statements for all statements which return a result set. Good or bad?

• What are (server-side) Prepared Statements?
• Pro’s and Con’s
• MySQL myths
• MySQL specifics
• …

Server-side Prepared Statements are an outdated technology from ancient times, are they? Brian gives a long list of arguments in his blog posting “Prepared Statements, Musings” why one should think twice before using server-side prepared statements. PDO does enforce the use of prepared statements for all statements which return a result set. Good or bad?

• What are (server-side) Prepared Statements?
• Pro’s and Con’s
• MySQL myths
• MySQL specifics
• …

In yet-another sign of the consolidation of the infrastructure business, Progress Software announced the acquisition of IONA. IONA, with headquarters in Dublin and Boston, was a high flyer in the 90s with the development of the first implementation of CORBA, a key middleware technology for integration. While the company stumbled in later years, they have been retooling around SOA (Service Oriented Architecture) including their open source Artix technology. So raise a pint of Guiness for IONA as it enters into the next chapter of its history. Go mbeire muid beo ar an am seo arís.... READ MORE