Conceptually that is fine but there are complications (speaking based on recent and ongoing experience on a project I'm working on): 1. When you have multiple

Conceptually that is fine but there are complications (speaking based on recent and ongoing experience on a project I'm working on): 1. When you have multiple entity tables that are inter-related, snapshotting one in isolation is not sufficient. 2. When only certain changes on certain fields should result in a new snapshot. Granted, both of these are solvable with built-in Postgres mechanisms (and a bit of co-operation from the application server) but simple it is not. In our case we also move historic records to a second 'history' table.