In my current project I have a customer requirement for implementing a change log. This is not just for auditing purposes, rather it is meant to be accessible by users so they can get an overview of the change history of an object. The entire data set is not big, I'm expecting considerably less than 50.000 records. Changes are only made by about 30 human users. Queries related to change history are (a) for all changes during a specific time interval and (b) for all changes to a particular record. My original intention was to keep two sets of tables. The first containing only the working set of current records. The second containing all prior versions. I haven't experimented with such a setup yet and I'm wondering if it is even necessary. The alternative being to keep only a single set of tables. Can anyone relate their experiences with such a thing? Which approaches should I take into consideration? Michael -- Michael Schuerig Face reality and stare it down mailto:michael@xxxxxxxxxxx --Jethro Tull, Silver River Turning http://www.schuerig.de/michael/ ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org