Hi Dave,
As Gustaf mentioned, we made some modifications in our installation in order to have a better performance when moving from PG 8.3 to PG 9.0. The changes mostly affect permissions.
Basically one has to run a couple of scripts and change some xql files. So the code is not in reality much. Everything is packaged in its own package so applying the changes should not be hard for a stand alone openacs installation; the only thing is that steps for upgrading need to be well stablished so people dont get lost. So, Ill try to dedicate a couple of hours this and next week and do some clean up and docu ( and some testing ;) ).
Best,