At the db level, Oracle provides "Database replay" feature. that lets you replay the production server events in the development/test environment. http://docs.oracle.com/cd/B28359_01/server.111/e12253/dbr_intro.htm Won't something like this be useful in PostgreSQL? It will let us mimic the production environment load and analyze it better.
Some of the features currently under development right now will make this sort of thing easier to build into the core database. For example, the recent "Command Triggers" feature submission will make it easier to catch DDL changes as well as queries for this sort of thing.
