Hi Orzenil,
I initially ported the clickstream package from acs to openacs 4, and Surath ported the Oracle datamodel to PostgreSQL.
Personally I feel the Clickstream package should be deprecated in favour of the user-tracking and clickthrough packages. They are lighter weight and provide the same functionality, if not more than the Clickstream package. Plus the datamodel is a nightmare, as it was developed at a time when everything was done in the database, so there are lots of database procedures. These procedures should really be moved to a TCL library, if future work is to be one on this package.
Cheers,
Nick.