Why are the best technical books also the thinnest? To make the case, I highly recommend the MySQL 5.1 Cluster Certification Study Guide In rack units, it’s a 1U; it fits nicely into my laptop bag; and if you’re considering implementing MySQL Cluster, it can save you a world of time.

Of course, if you get the book, you should consider the certification itself. There’s a legitimate debate about the usefulness of certification exams, but the MySQL 5.1 Cluster certification is a little more important than others for a couple of reasons:

1. In case you haven’t heard it by now, Cluster isn’t always the best fit. In many cases, an active/passive failover setup is a much more flexible and cost-effective approach. It’s not always a clear-cut decision. If you’re willing to make application changes …

A new edition of the MySQL 5.1 Cluster Certification Study Guide is due out any day now. As soon as I get the new on the availability, you will see it here. It will be bigger, better, and all the marking adjectives you would ever want.

But the original, first printing is sold out.