Just a quick note to let folks know I'll be doing a presentation on Join-Fu: The Art of SQL, tonight in Cincinnati. Thanks to Elizabeth Naramore for inviting me down to OINK-PUG (Ohio-Indiana-Northern Kentucky PHP User Group)!

I'll be covering both Beginning Join-Fu and Intermediate Join-Fu tonight. Topics covered include:

• Schema optimization and vertical partitioning
• SQL Coding style guidelines
• Set-wise problem solving in SQL (and why it kicks for-loop-fu's ass.)
  • Rewriting correlated subqueries into joins
  • Using derived tables or subqueries in the FROM clause
  …

Well, neither did I until today. HA!

Velocity is a new O'Reilly conference dedicated to "Optimizing Web Performance and Scalability".  It starts next Monday.  Yesterday I was contacted by Adam Jacobs of HJK Solutions about taking part in a panel discussion about what happens when success comes suddenly to a web site.  I think he thought I was in the bay area.  Little did he know I am in Alabama.  But, amazingly, I was able to work it all out so I can be there.  I wish I had known about this conference ahead of time.  It sounds really awesome.  Performance has always been something I focus on.  I hope to share some and learn …

I am giving a talk titled "An Introduction to MySQL" here in Birmingham, AL on June 21, 2008 at 3PM.

I love living in Alabama.  I was born and raised in Huntsville.  However, Birmingham has always seemed a bit behind in technology compared to what I do for a living.  There is good reason.  The industry here is medical, banking, industrial and utilities.  I don't really want my doctors keeping my medical records in an alpha release of anything.  Same goes for my banking and utilities.  But, as this page shows, the companies here are catching up.  So, I am happy to present MySQL to as many people as I can in this town.  Hopefully I will help some folks that have not been exposed to MySQL or any open source for that matter.
…

I’m going to OSCON in July, and I know that just about everyone I know who is a participant in this crazy life we call IT (or web 2.0, or whatever it’s called now), is flying to a conference or something in 2008. I’m starting to notice more and more posts like this one, so if you can avoid it, don’t put anything in a checked bag that you can’t afford to lose, and avoid US Airways, and pass it on, because when you see the list of things they don’t cover in their lost baggage policy, you’ll suddenly feel like you’re lucky to still have anything you ever checked with your bags.

MemProxy 0.1 is out!  It has taken me a while, but I have finally gotten around to releasing the code that I credited with saving us during a Yahoo! mention.  It is a caching proxy "server" that uses memcached for storing the cache.  I put server in quotes because it is really just a PHP script that handles the caching and talking to the application servers.  Apache and other HTTP servers already do a good job talking HTTP to a vast myriad of clients.  I did not see any reason to reinvent the wheel.  Here are some of the features that make it different from anything I could find:

• 
  
• Uses memcached for storage
  
• Serves cache headers to clients based on TTL of cached data
  
…

So, we had a cron job hanging for hours.  No idea why.  So, I started debugging.  It all came down to a call to in_array().  See, this job is importing data from a huge XML file into MySQL.  After it is done, we want to compare the data we just added/updated to the data in the table so we can deactivate any data we did not update.  We were using a mod_time field in mysql in the past.  But, that proved to be an issue when we wanted to start skipping rows from the XML that were present but unchanged.  Doing that saved a lot of MySQL writes and sped up the process.

So, anyhow, we have this huge array of ids accumulated during the import.  So, an in clause with 2 million parts would suck.  So, we suck back all the ids in the database that exist and stick that into an array.  We then compared the two arrays by looping one array and using in_array() to check if the value was in the …

Hi. My name is Brian, and I’m a tech bibliophile.

I have owned more books covering more technologies than I care to admit. Some of my more technical friends have stood in awe of the number of tech books I own. I am also constantly rotating old books that almost *can’t* be useful anymore out of my collection because there’s just no room to keep them all, and it would be an almost embarrassingly large collection if not for the fact that I have no shame or guilt associated with my need for dead trees.

If you need further proof:

• I have, on more than one occasion, suggested to my wife that we take a walk around our local mall so I could browse the computer section of the book store, not to buy, but just to keep up with the new titles and stuff.
• Ok, I usually buy.
• I also go into book stores whenever I’m out of town to get a comparison of what seems to be popular in different areas of the …

UPDATE: if anyone knows of a non-broken syntax highlighting plugin for wordpress that supports bash or some other shell syntax, let me know :-/

Apache logs, database backups, etc., on busy web sites, can get large. If you rotate logs or perform backups regularly, they can get large and numerous, and as we all know, large * numerous = expensive, or rapidly filling disk partitions, or both.

Amazon’s S3 service, along with a simple downloadable suite of tools, and a shell script or two can ease your life considerably. Here’s one way to do it:

1. Get an Amazon Web Services account by going to the AWS website.
2. Download the ‘aws’ command line tool from here and install it.
3. Write a couple of shell scripts, and schedule them using cron.

Once you have your Amazon account, …

SimpleXML is neat.  Some people don't think it is so simple.  Boy, use the old stuff.  The DOM-XML stuff.

Anyhow, one annoying thing about SimpleXML has to do with caching.  When using web services, we often cache the contents we get back.  We were having a problem where we would get an error about a SimpleXML node not existing.  We were caching the data in memcached which serializes the variable.  So, when it unserialized the variable, there were references in there to some SimpleXML nodes that we did not take care of.  Basically, a tag like:

<foo>bar</foo>

is a string.  But a tag like:

<foo></foo>

is an empty SimpleXML …

Do you use mod_auth_mysql, the Apache module that allows authentication of users to happen through a MySQL database?

If so, the nice folk at Automattic (makers of fine blogging software like Wordpress) have released a patched version that works with phpass.

With this, you can now have single sign on (SSO), with authentication against a WordPress blog (or bbPress forum). Note that WordPress (in 2.5 and later), doesn’t use MD5 hashes to store passwords any longer; instead they are salted and hashed with the phpass library. The Automattic folk use this to provide SSO for Trac and Subversion.

Read …