“The key, the whole key, and nothing but the key, so help me Codd!”

The database guys should like that one. Can’t remember where I saw it today to acknowledge reference.

Well, it’s Sunday night so I will put this down to being the weekend. The background to being caught out is a request I made to my local Users Group mailing list for some information on people’s environments because I wanted to some empirical data analysis without having any more knowledge of the systems.

In summary (without the surrounding fan-fare, I was seeking):

SELECT VERSION();
SHOW STATUS;
SHOW VARIABLES;  // Optional

I was however perplexed why my first data point analysis (Read/Write ratio) using the Status values Com_insert, Com_update, Com_delete and Com_select was not always giving me expected results. In particular, a number of server results showed 0 for values while I knew the results came from working MySQL environments.

So, sanity check with good friend Morgan and I get the response to answer the dilemma SHOW STATUS defaults to session …

No, it’s not a bedtime story, is a serious system’s design concept and I’m amazing that people don’t know about this.
As I mentioned in If you don?t know your data, you don?t know your application I was doing a Java Code Review, and I found a clear case of a much simplier solution. How simple you ask?

Well, without completing the task 100%, I achieved in less then 1 day (and lets say for the argument 1 more day of work), what is being worked on by somebody else for a week, with an estimate of 2 more weeks to complete. So let’s add 50% to my estimate, that’s a total of 3 days verses 15 days. You do the math. and yes that was last week and that task is still being worked on the same way, even with reference to my working code. Not to mention the code is a similiar magnitude of simplicity, and simplicity means cost savings in support, people so quickly forget …

The art of data modelling is definitely lost on some [most] people, or they never found it, even though they think they did. Over dinner with good friend Morgan last night we were swapping present stories on the topic.

Morgan wrote recently about I want my 4 bytes back damn it., and interesting example storing an ISBN. Further reference can be found at Getting started with MySQL of a more impractical ISBN example.

Disk is cheap now, so the attitude and poor excuse can be, well a few extra bytes doesn’t matter. Well no! If your a social hacker and have a website with a maximium concurrent connections of 2 maybe, but much like some recent Java Code Reviewing I just performed, just because the system isn’t 24×7, …

Just came across a good article by Jay Pipes talking about lazy loading and caching of content. A nice read with some good code examples that I thought I should share with my fellow readers.

Read Jays blog entry

I’ve recently completed a contract and I’ve been in discussions with agents and other employers for further work. Having had one of the worse experiences in my previous work, I’ve been extra careful to ensure what I’m told at the interview/meeting stage is indeed true and accurate (in my last case it was not). I’ve also not made the assumption that an organisation that is dependent on software has placed a certain level of value on what’s in place. (in my last case I did, simply due to the size of the organisation and volume of business).

So, when being asked by people what I’m seeking, outside of the technical skills and compendencies, I’m seeking an organisation that places value on it’s existing software, it’s software quality, it’s software improvement and most importantly it’s software developers. It was unfortunate that for an organisation that lived in software, and would not survive long (especially at …

Today Peter Zaitsev announced launch of new forums related to MySQL Performance questions. He says:

This forum is created as free alternative to MySQL Consulting Services which we provide. If you would like to get some free help to your performance issues please use forums so everyone else could benefit from our replies. You also should get more opinions on your performance problems from other forum members. There were a lot of unrelated performance questions placed as comments and sent by email and we had to find better way to organize it.

I think that it is a great idea to start such forums ontop of great blog site because many people can find it from Google when looking for some performance related questions or discussions. So, I want to say good luck to peter and will try to participate any discussions in these forums.

Should you want to be on the bleeding edge, or in my case, don’t want to download 70MB each day in a daily snapshot (especially when I’m getting build errors), you can use Bit Keeper Free Bit Keeper Client that at least lets you download the MySQL Repository. This client doesn’t allow commits, which is a good thing for those non-gurus in mysql internals (which definitely includes me).

wget http://www.bitmover.com/bk-client.shar
/bin/sh bk-client.shar
cd bk_client-1.1
make

By placing sfioball in your path you can execute.

sfioball bk://mysql.bkbits.net/mysql-5.1 mysql-5.1

This took me about 4 mins, which seemed much quicker then getting a snapshot!

You can then get cracking with my instructions at Compiling MySQL Tutorial 1 - The Baseline.

A good reference …

Just to confirm my earlier confusion about verified snapshots at Compiling MySQL Tutorial 1 - The Baseline.

“Daily snapshot sources are only published, if they compiled successfully (using the BUILD/compile-pentium-debug-max script) and passed the test suite (using make test). If the source tree snapshot fails to compile or does not pass the test suite, the source tarball will not be published.”

Seems the fine print at MySQL Database Server 5.1: Beta snapshots also states this. Well, need to take my RTFM pill there.

Thanks to Lenz for putting the record straight, and helping with my Forum Post. Seems I did uncover a Bug, now recorded as …

Pre-requisites

This tutorial is aimed at Linux installations that has the standard development tools already installed. The INSTALL file in the source archives provides good details of the software required (e.g. gunzip, gcc 2.95.2+,make).

Create a separate user for this development work.

su -
useradd mysqldev
su - mysqldev

Get an appropiate Snapshot

You can view recent snapshots at http://downloads.mysql.com/snapshots/mysql-5.1/.

The official statement on snapshots from MySQL AB.
Daily snapshot sources are only published, if they compiled successfully (using the BUILD/compile-pentium-debug-max script) and passed the test suite (using make test). If the source tree snapshot fails to compile or does not pass the test suite, the source tarball will not be published.

At the time of producing …