In my travels I do a lot of analysis of the slow query and the general query logs. In many Java shops I end up seeing the most frequently called command is

set autocommit=1;

Sometimes this statement is called 300-400x more then any other statement. What’s surprising to most of these shops, is that they are leaving autocommit on… so logically they are baffled why the statement is appearing over and over again. You see by default the autocommit statement wraps the calls to the database. So if you trace the calls you will see:

set autocommit=1;
select * from sometable
set autocommit=1;

Yep, even select statements see this behavior. So what, Its a small set statement right? . But that small set statement has to traverse the network, be parsed, be executed, then return something. Lets assume that adds 2ms to your transaction, over the course of a day that’s going to really add up. Over a million queries that …

I?ve been reading The Bee Keeper (also here in PDF), an explanation of the relationship between professional open source software (POSS) vendors and their communities, written by Pentaho?s CTO James Dixon. It is a very elegant explanation of the development/business model employed by the POSS vendors such as MySQL, Pentaho, JBoss and Alfresco.

James uses the analogy of the Bee Keeper to explain the model. It?s worth reading the paper in its entirety to understand just how appropriate this is but to put it very simply: the vendor is the bee keeper; the community is the bees; the open source project is the honey; and the customer …