This is another article in a series of articles titled "A few notes ..." in which I will be posting some important information about locking concepts, different types of locks and what locks table engines support. Just like the previous article, the purpose of this article is to highlight important aspects that you should have in the back of your mind when developing applications.

MySQL Conference 2009 is coming around the corner, next week, in Santa Clara.

You may want to delve into the notes, as a fast way to learn about the happenings.

If you want to become an active code contributor to MySQL, the hackfest by Mark Callaghan seems interesting, and you should probably also start here and here. 

There will also be a special BoF geared to community contributors. (I still haven't been able to find out about the exact timing of this but you should be …

MySQL Conference 2009 is coming around the corner, next week, in Santa Clara.

You may want to delve into the notes, as a fast way to learn about the happenings.

If you want to become an active code contributor to MySQL, the hackfest by Mark Callaghan seems interesting, and you should probably also start here and here. 

There will also be a special BoF geared to community contributors. (I still haven't been able to find out about the exact timing of this but you should be …

MySQL Conference 2009 is coming around the corner, next week, in Santa Clara.

You may want to delve into the notes, as a fast way to learn about the happenings.

If you want to become an active code contributor to MySQL, the hackfest by Mark Callaghan seems interesting, and you should probably also start here and here. 

There will also be a special BoF geared to community contributors. (I still haven't been able to find out about the exact timing of this but you should be …

These are the slides I have shown at my security talk (Room F at 11.50am today).

Security and the real world (PDF, 1.4 MB):


Continue reading "Security and the real world"

In Serving Images from a Database, Sheeri responded to me: I appreciate your ideas, but you haven't read what I've written: "the sheer number of files is enough to kill any os."

I'm serious about that. we're talking 36 million images -- that's 36 million files (no thumbnails, they're all reduced size) plus directories to store them in. We have cacheing tuned very well, and it's still kills the OS.

Here is what I tried to simulate that:

I took my new Strato MR2. It is currently running tor, INN and MySQL. There are two HDS722516VLSA80 160 GB SATA HDDs. These disks are rated at 8.8ms avg seek time, so there are 113 seeks …

Sheeri wrote: So, most of the “I want images in MySQL” conversations are terminated with “Don’t.” People do say this for a reason. Here is the story of your request going through the system:
Continue reading "Serving Images From A Database"

In Is MySQL simple or complex (or both)?, Mike Kruckenberg asks: So the question is . . . What happens to the people who really just wanted a simple, no frills, easy to use database. Based on the message, MySQL is no longer the database for them. Right?

MySQL 5.0 has gained a lot of features, and some of these features such as the procedural extensions, are as often a benefit for a project as they are creating problems for a project due to feature abuse. Having more features makes the product larger and more complex as well. So, yes, 5.0 is a lot more complex than older versions, and it carries around a lot of baggage that many traditional MySQL users don't need - and yet the same features are crucial for others.

This dilemma one reason why I look forward to the beginnings of modularization that we see with 5.1 - loadable …

As reported earlier I have been taking the MySQL core and pro exams. This morning I found two letters from Denmark in my mail, wherein The Company deemed me fit and bestowed upon me the vast powers of the Certified MySQL Professional.

My certification IDs are 73899 and 74024 and the password is "public".

If you run the following program as a non-root user, you will see exactly how much memory a single process can allocate on your Linux system. The program is simple, it gets memory in 1MB chunks until it is shot down by the Operating System. In order to prevent overcommitment, the memory allocated is actually written to with memset().

On a Debian 2.4 smp kernel with 4 GB of RAM, it stops at 2933 MB.

(via Torsten Sievers)


Continue reading "How much memory can a process use?"