A few meetups ago, we had Jim Starkey come and speak. During that evening, he asked “Why is MVCC not serializable?” It was a “go and do your homework” kind of question.

So, in order to answer that question, let’s explore the concepts of isolation and concurrency, the “i” and “c” in ACID compliance. For this post, I will refer to “transactions”, by which I mean actual transactions, as well as statements where autocommit=0. In other words, every statement is its own transaction, unless it is within an explicit transaction, and for the purpose of this article, those statements are “transactions”. Of course, for many of the explanations below, if there’s only one statement in the transaction, there’s no problem. (As usual, if I make a mistake, please correct me. I will make sure all comments from all sources get to the article at …

Do you know the fine details of MySQL's transactional error handling with the InnoDB storage engine? If you're writing transactional SQL, you need to be prepared to handle errors appropriately, and to do that, you need to know how MySQL handles them. This article introduces you to the topic.

If you’ve been using the Event Scheduler that was introduced in MySQL 5.1.6, there are some changes in the workings of the event_scheduler server variable. These changes are fairly simple — but not trivial — and were just committed to the 5.1 tree a few days ago. They will definitely be part of the official 5.1.12 release — which should be out just about any day now — so you’ll want to be aware of them, and how they’ll affect the behaviour of the Event Scheduler, before you upgrade.

This variable determines whether the Event Scheduler is available, and whether it’s actually running. In MySQL 5.1.12, it can be used in either of two ways:

1. a server option that can be used from the command line (--event-scheduler), or in the …

We released Zimbra 4.0.2 today and there were a few extras that came along for the ride. First off the Fedora Core 5 build is now GA. We also added a new developer/preview release on Ubuntu. This has been a popular hack in our forums for sometime.

Here's a sample of some of the other changes/fixes in 4.0.2:

- perf improvements for IMAP (new MySQL indexes)
- > 2GB support in the Zimbra Outlook Connector
- i18n and some l10n for the Zimbra Outlook Connector
- disabling AS/AV causes mail deferral
- cursor fails to appear in Firefox
- mailbox quota page does not contain any entries
- several all day event and timezone bugs fixed

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Breach Acquires ModSecurity Open Source Vendor Thinking Stone; Founder Ivan Ristic Joins Breach As Chief Evangelist, Breach Security (Press Release)

Nexaweb Closes $10 Million in Funding, Nexaweb (Press Release)

GPLv3: recent misleading information, Free Software Foundation (Press Release)

Qlusters Announces the Availability of openQRM Pro, Qlusters (Press Release)

…

MySQL AB will host two European Customer Conferences next month - in London on October 17, and in Munich on October 19. For conference details and registration information, go to http://www.mysql.com/news-and-events/european-conferences/.

Do you know the fine details of MySQL’s transactional error handling with the InnoDB storage engine? If you’re writing transactional SQL, you need to be prepared to handle errors appropriately, and to do that, you need to know how MySQL handles them. This article introduces you to the topic. How InnoDB differs from other engines When a MySQL query has an error in a non-transactional storage engine, such as MyISAM, the results are anybody’s guess.

There's an interesting survey of Red Hat's partners by Bank of America that crossed my desk recently.  Ok, I admit, I have been burried for the last couple of months; the survey was from June and I should have picked up on it earlier since it's been covered by both Forbes and Matt Asay's blog over at InfoWorld.  (Ok, I don't usually find Forbes all that great a read; too old school for me.  But how did I miss Matt's posting?)  Still, it's quite interesting reading, especially in light of Red Hat's introduction of a software stack. 

Bank of America Securities spoke to 130 Red Hat partners across all …

The development of Connector/ODBC v5 has been ODBC Centric. Who cares and how important is this distinction?

The folks who care the most are those that get into the C/ODBC code in the hopes of tracing down a bug or otherwise enhancing the code. You see; developing C/ODBC with an ODBC centric frame-of-mind means that anyone who understands the ODBC specification, even superficially, will find the code approachable. Presumably anyone using the ODBC driver will have some understanding of ODBC and certianly those savy enough to dive into the C/ODBC code.

The different frame-of-mind manifests itself in a wide variety of ways all of which makes cross-referencing to the ODBC specification much easier. For example;

• Naming conventions, from files to variables, are more meaningfull from an ODBC perspective.
• Reduction and isolation of references to MySQL specific code (loose coupling) reduces need to understand both …

I have been a consultant for long time. It is an interesting job, which has given me much satisfaction. The coolest part of the job is the inner pleasure you feel when you solve a difficult problem in a few minutes, earning a reputation for being a wizard.
The negative part of the job is being alone. As a consultant, you are supposed to know everything, and as such you don't have anybody to talk with when you have doubts (and if you are really good you must have doubts from time to time). Well, this condition makes you stronger, and improves your confidence, but your interaction with your co-workers is quite weak.
So I decided to try a new career for a change, and to cash on my experience and knowledge of databases in general and MySQL in particular. And which position should be more suitable than one at MySQL AB itself?
I applied for a couple of jobs at MySQL, got two offers, chose the one that appealed me the most, and here I am. …