Archive for MySQL

Maximum length for BLOB columns in MySQL

Well, that was interesting. I was debugging a problem with a particular uploaded document on Insightory, and it looks like I made the wrong decision when choosing the datatype for a blob column in one of my tables.

Apparently MEDIUMBLOB stores up to 16 MB of data, and the uploaded document was larger than that. Not a big deal, I’ll go ahead and accept blame and fix the table schema and move on.

However, when trying to research on this and find the maximum length for BLOB fields in MySQL at the manual, I get this pretty data table with some formulas on how to calculate the maximum number of bytes myself. Isn’t that helpful?

How about the members of the documentation team pre-calculate this stuff for me, so I can just read and absorb the content without taking out my calculator? Mmkay thx bye.

Random interesting things from MySQL Conf 2008

Some interesting projects / products I learned while attending the MySQL Conference 2008:

  • PDO_MYSQLND – A new PDO extension that is compatible with PDO_MySQL, but uses the mysqlnd library to deal with the database server.
  • DbUnit – an extension to standard PHPUnit to deal with database-related unit tests.
  • Buildbot – cool little utility that lets you automate a lot of tasks to achieve continuous integration of software projects. I need to play with this and see if it would work for some of our unit tests.
  • Varnish – a new high-performance reverse proxy, kind of like Squid, but made for this type of work.

Took me a while to publish this draft :(

New location for monthly Houston PHP / MySQL Users Group meeting

I’m happy to announce that we are finally changing the location for our monthly meetings, from the dreaded University of Houston main campus to a Galleria location.

Alert Logic has agreed to host the monthly meetings at their headquarters (we are next to the Marathon Oil building), so hopefully this will make it easier for people to attend. I’m looking forward to having a real meeting room with projector and wireless internet for a change!

I’ll be updating the meeting details today, but our new location will be the following:

Alert Logic, Inc.
1776 Yorktown
7th Floor
Houston, TX 77056

Driving directions from Downtown:

1. Head north on Travis St
2. Turn left on Walker St – go 0.4 mil
3. Take the I-45 North ramp – go 1.0 mi
4. Take exit 48B onto I-10 West – go 5.1 mi
5. Take exit 763 onto I-610 South – go 1.5 mi
6. Take exit 9B to Post Oak Blvd – go 0.8 mi
7. Turn right on Post Oak Blvd – go 0.5 mi
8. Turn right on San Felipe – go 0.6 mi
9. Turn left on Yorktown – go 0.1 mi

Velocity conference coming up in June 2008

Velocity is the new O’Reilly conference aimed at discussing topics related to scaling web sites and applications on the Web. It seems really interesting, and I will try to attend.

Having access to some of the industry’s experts in scaling web sites will be really useful. In fact, Steve Souders is one of the program chairs of the conference, and he is also known as the creator of the very popular YSlow extension to Firefox.

Thousands of tables in a MySQL database

Just read about the potential performance implications of having thousands of tables in a single MySQL database over at Ask Bjørn Hansen’s blog.

We have that type of setup at Alert Logic, but I don’t remember any problems while shutting down the database server. I wonder if the FLUSH TABLES problem only happens that badly under MyISAM instead of InnoDB?