We're currently in the process of porting acs to work with both oracle and postgresql as a data-base back-end. It' a fairly large task as acs 4.x is highly dependent on an extensive set of pl/sql procedures. You can look at our current
status to get an idea of how it's going.
Essentially, you have to convert the pl/sql procdeural language api and the data-model to work with db2, and you would need to extract and port the db2-specific queries from the .tcl scripts. SQL92-specific queries have already been ported, so your work would be alot less than what we've encountered when porting to postgresql. In addition, making it work with db2 would be somewhat easier, as we've laid the foundation for openacs to work with multiple db's, by adding a query-dispatcher and modifying the package manager to work with multiple db's.
It would be interested in hearing if anybody else would be interested in doing a port to db2, though it might be better to wait until we're done porting openacs to work on oracle and postgresql. That way you'll have a better chance of getting more volunteers to help out.
