I've just been implementing audit trails in an application because of the FDA's 21CFR11 part 2 (electronic records rule, which also covers electronic signatures). The audit trail records date, time, user, tablename, fieldname, old value, new value, transaction type (Insert, etc.).

What always strikes me with audit trails of a record is that the original record is, logically, not needed at all - it can be entirely reconstructed from the audit-trail. Logically (or philosophically), perhaps the audit-trail IS the "record" and the single record in the original table merely an instance holding the current values: in effect, a "certified image" of the current values held for quick access and nothing more.

The thought-experiment, then:

Given a fast enough server, could one remove the need for the original record or even the record's table itself, if the audit table holds table-name and field-name. As this is a thought-experiment, we will posit a server so fast it could reconstuct a record from a log of all the actions for a 'virtual' record without noticable delay, or at least not slower than your current system: can anyone see how the result from this would differ from a single record holding the current values? I cannot.