I spent far too much time this past week trying to find out why a Drupal was not  assigning authenticated user permissions to users who clicked on the validation link they were emailed. Instead, it would simply remove the temporary unverified user permission.

It's supposed to do the latter, but then also follow it up with the former. It turns out the problem was a Drupal bug that was triggered by my MySQL setup.

My Drupals all use a server that is a master in a set-up with two masters an three slaves. This has some implications for the auto_increment integer data type. In order to avoid clashes when two masters each insert a new record simultaneously, a master gets a specific instruction about which IDs it may assign.

These instructions specify how many numbers to skip - typically the number of masters in a cluster - and an offset to add, …

If you saw Don MacAskill's keynote (The Smugmug Tale) at the recent MySQL Conference and Expo, you know that he had lots of positive things to say about his experience running MySQL on the Sun Storage 7410 at Smugmug. The 7410 marks the current high end of the Sun Storage 7000 Unified Storage line of network attached storage devices. For the past few months, I have been investigating MySQL database performance on the entry level and mid-range models, to see whether they might provide similar benefits to smaller MySQL sites. I have to admit that I was more than a little …

If you saw Don MacAskill's keynote (The Smugmug Tale) at the recent MySQL Conference and Expo, you know that he had lots of positive things to say about his experience running MySQL on the Sun Storage 7410 at Smugmug. The 7410 marks the current high end of the Sun Storage 7000 Unified Storage line of network attached storage devices. For the past few months, I have been investigating MySQL database performance on the entry level and mid-range models, to see whether they might provide similar benefits to smaller MySQL sites. I have to admit that I was more than a little …

I've been on vacation this week, and decided to fine-tune some old QA code. Opened the manual to see the syntax for a select statement, and afterwards added to my random select generator the following:

• all index hints (force, use, ignore, for join, for order by, for group by)
• lock in share mode, for update
• key_block_size for individual indexes
• hash, btree, rtree for individual indexes
• unique, fulltext, spatial for indexes

Especially important is the 'lock in share mode' addition. The reason is InnoDB
has many serious bugs with this locking mode (insert ... select, and others) in read committed mode.

So, I don't need multitable delete or update to reproduce those bugs, since I can just do a simple select locking in share mode. For example, the following bugs previously went without proper testcase until I discovered this:
…

You crash MySQL/Innodb and you trace the error to a function that says:

“This function checks the consistency of an index page when we do not
know the index. This is also resilient so that this should never crash
even if the page is total garbage. ”

Oops… I guess its not that resilient after all:)

Mark Leith, on of the MySQL Support Team managers wrote some time ago a very nice utility I use often called Statpack.

My use of Statpack is very simple. Take two snaphots of SHOW GLOBAL STATUS and compare to produce a text based version of the statistics.

Over time I’ve grown to love it’s simplicity, but notice a number of shortcomings. Being open source there is always the ability to modify, improve and give back. This post is more about detailing those little annoyances that I’d like to improve, or see improved. It is also a means to collate points into one location that I often forget about over time.

I welcome any input, and specifically help in this open source venture.

Here is my wish list that I can currently remember. I do plan to action, time permitting.

1. In Statement Activity, the total percentages are great to …

It was long ago observed that efficiency of code depends on its appearance. Good code is usually readable and quickly understood by colleagues. Of course, code formatting won’t speed up the execution of your queries, but will definitely simplify finding the errors and prevent ambiguity.

Make your code standards-driven and clear for other people using formatting functionality of dbForge Studio for MySQL. Based on your needs, you can benefit from 3 types of formatting:

• Automatic
• Manual
• Using SQL formatter wizard – to format multiple SQL files at once.

By default, when you finish a statement with a delimiter or paste any code fragment, they automatically formatted.

In case you want to format SQL code manually, decide whether you want to format …

A lot of folks are unclear on the subtleties of free software and open source. Mike Hogan writes a blog article"Is Hybrid Licensing of OSS Hypocrisy?" to try to shed some light on this. With respect, I think he has missed part of it.We're talking about two orthogonal things here. One is open-source versus closed-source, and the other is whether we charge money for software licenses or not. As

EC2 is nifty, but it doesn’t appear suitable for all needs, and that’s what this post is about.

For instance, a machine can just “disappear”. You can set things up to automatically start a new instance to replace it, but if you just committed a transaction it’s likely to be lost: MySQL replication is asynchronous, EBS which is slower if you commit your transactions on it, or EBS snapshots which are only periodic (you’d have to add foo on the application end). This adds complexity, and thus the question arises whether EC2 is the best solution for systems where this is a concern.

When pondering this, there are two important factors to consider: a database server needs cores, RAM and reasonably low-latency disk access, and application servers should be near their database server. This means you shouldn’t split app and db servers to different hosting/cloud providers.

We’d like to hear your thoughts on EC2 …

In a comment to my prior post , Roland Bouman raised the issue mixed messages inherent in the dual-licensing model of open source. There is more context to his comment, but he says: "I am all for commercial open source. I am just curious how you feel you can logically defend both ‘take us we’re open and free’ and ‘take us we offer quality paid for extras’."

There are many articles written on the topic of free open source and hybrid models, so in the words of Inigo Montoya from Princess Bride: "… let me ’splain. No, there’s too much. Let me sum up."

Open Source Software (OSS) is a …