I've written a few times about database consistency before, mainly in conjunction with NoSQL and the concept of Eventual consistency. Now, I'm about to do an update on the subject, as I have come to realize a few things.

From an oldtimer like myself, having been an SQL guy for 25 years, I remember Punk-rock and even The Beatles and I having hair growing out of my ears, what can be contributed? Well, let me beging with stating what I mean when I say Database consistency. What I mean is Consistency as the C in ACID (no, we aren't talking drugs here, we are talking databases). Let's see what the online authorative reference work on just about anything on this planet, from the size of J-Lo's feet to the number of Atoms in the universe (those two numbers are quite far apart by the way), Wikipedia: "The consistency property ensures that any transaction will bring

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Having just written an interview response about NoSQL concepts for a RDBMS audience it was poetic that an inconspicuous title “(4 of 3)” highlights that both a MySQL read scalable implementation via replication and a NoSQL solution can share a common lack of timely consistency of data. For the sake of Group Commit I hope my data is always consistent at some location at some point in time as soon as possible.

In attempting to comment to Kristian Nielsen’s Fixing MySQL group commit (part 4 of 3) I was forced to watch an ad before I could even add a comment. Go jump Live Journal, it’s quicker to write my own blog post.

And if anybody is still reading, I had just written the following.

“There is clearly a place for NoSQL solutions. The two primary types of

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In the first article in this series on archiving strategies for online transaction processing (OLTP) database servers, I covered some basics: why to archive, and what to consider when gathering requirements for the archived data itself. This article is more technical. I want to help you understand how to choose which rows are archivable, and how to deal with complex data relationships and dependencies. In that context, I'll also discuss a few concrete archiving strategies, their strengths and shortcomings, and how they can satisfy your requirements, especially requirements for data consistency, which as you will see is one of the most difficult problems in archiving.