I'm moving my blog from http://gnu.inter.it/blogs/ilcorra/archives/cat_mysqlen.html to http://blog.pandiani.com

My new MySQL related XML feed is http://blog.pandiani.com/category/mysqlen/feed

Please update your links

Thanks

Scott Noyes wrote about a question frequently asked in for instance the freenode #mysql channel: given a table with students and answers, which students have answered all of a certain set of questions.

While his solutions are interesting, they do indulge a bit. And I'm not even referring to the fact that he uses obscure string and bit functions... he can do that if he wants to ;-) But it's a relatively simple problem that just does not need such (potentially inefficient) constructs.

For starters, it'd be good to have a WHERE clause, because even if there are many more questions in the table, you only need the As and Bs. You never want to use the HAVING as a replacement for WHERE, because having chucks away already retrieved rows from the result set, while WHERE limits what is retrieved in the first place.

Also, while it's very good to …

As we get close to the 1.0 release of our opentaps Open Source ERP + CRM system, I've been trying very hard to think about what future versions will do.

The immediate future is pretty easy to see: we have a good system for bringing together processes and data in a company. We can easily extend it to meet the needs more of more companies and industries. We'll also be adding tools for data analysis.

But what should opentaps 4.0 do? And how should it do it?

This is hard for me to see right now, but I could envision how future computers in general should work, so I'm going to jot down a few notes to help me think later:

In 2012, my computer is the size of a credit card. I'll take it with me wherever I go and turn it on either using a scan of my eye or my thumb. It comes with no monitor and no keyboard, but once turned on, it will project a …

I've been getting quite a few reports that my 5.0 and 5.1 installers don't work on Vista.  The reports all say that near the end of the install, it errors out with an error code of 2869. 

As a side note, I have yet to have an MSI error code that had a description that I  understood.  The description is almost always something like 'The transaction failed to start'.  These descriptions don't tell me anything.  But I digress.

This 2869 issue was hard to reproduce and very random.  After some work I found a 32 bit Vista machine that showed the problem.  With some trial and error and installutil style debugging I discovered that the problem was in my custom installer class.  Inside the MySql.Data assembly, we have a custom installer class that does two things.  First it adds the assembly to the system's machine.config file and then it adds a couple of performance counters.  …

While using the latest MySQL 5.1.20 yesterday I came across another situation that was not expected as with previous editions of MySQL. The background is experimenting with DRBD. When I configured MySQL to startup with a /etc/my.cnf file with data on a DRBD partition I got a failed startup error message with mysqld_safe.

$ bin/mysqld_safe &
[1] 12615
070720 10:10:42 mysqld_safe Starting mysqld daemon with databases from /drbd/data
070720 10:10:42 mysqld_safe mysqld from pid file /drbd/data/newyork.localdomain.pid ended

Ok. Well this happens so I went to the data directory to look for `hostname`.err.

$ cd /drbd/data
$ ls -l

What the! There is no error log. Then the discussion started about this. Apparently mysqld_safe now uses syslog (e.g. /var/log/messages) for logging messages. Ok, but where is the line between mysqld_safe and mysqld. …

The next couple days are gonna be a busy time here @ Zimbra.

July 22 - Ubuntu Live :: Collaboration in an Open World
"This session will explore the current problems with enterprise email, how the community can help fix it, how to leverage open source in mobilizing corporate email, and what's in store for the future of email."

http://www.ubuntulive.com/cs/ubuntu/view/e_sess/13492
Speaker: J.J. Zhuang, Server Architect


July 26 - The AJAX Experience :: Taking Large Browser-based Applications Offline
"How Zimbra managed to integrate several open source projects, including Tomcat, Jetty, Jakarta, MySQL and Firefox, to create an architecture for offline Ajax applications. "

…

No matter what system you run there are areas that just don't make any sense.  I love Visual Studio and will argue with anyone that it's the best way to develop traditional platform applications.  That being said, it's help system is quite ridiculous.

You would think that a company that is so focused on developer productivity would make it trivial to integrate third-party documentation.  The pages of the documentation are all just HTML files.  Each documentation package might contain some indexes but on the whole it's just HTML.  Here's an idea.  Just make the help format a zip archive and inside this zip you layout the HTML in whatever tree structure you like.  Include whatever scripts, CSS, or binary content you like.  Any top level pages that should not appear in the TOC can be listed in some .exclude file.  There can be a file that lists the name to file indexes.  All of this could then …

The 54th edition of Log Buffer, the weekly review of database blogs, has been published by Paul Gallagher on Tardate 10.2. Jeremy Schneider and the Ardent Performance Computing Blog take over next week. After that, the schedule is open, so please get in touch if you’d like to edit and publish a Log Buffer [...]

I have officially moved my blog from www.bytefx.com/blog to www.reggieburnett.com.  Please update your links, bookmarks, readers, etc.  I have attempted to preserve as many of the old dasBlog URLs as I can but I know of at least 3 URL types that are not working currently.  I'll try to get those working over the weekend.  If you find any old URL that is not working, please drop me a line so I can fix it.

Thanks!

I had been thinking of moving my blog for some time now.  I started my blog back when I was self-employed and operating under the corporate name ByteFX.  I have been employed by MySQL now for more than 3 years and been blogging about all things .NET and MySQL at my ByteFX site.  While technically there is nothing wrong with this, it always felt wrong to me to blog about my efforts at my current employment under a different corporate website.  The domain name 'reggieburnett.com' was available so I jumped.

GoDaddy.com offers some very cheap Windows hosting so I decided to host my new site and blog there.  They offer a very professional setup and the only real hang up was that my site had to be medium trust compatible.  dasBlog, my current blog software of choice, is not.  So I made the move to Subtext, a BSD-licensed fork of .Text.  It's simple, SQL-based (soon to support MySQL), includes a photo …