From bug 20612 comment 23.
(In reply to Tomás Cohen Arazi from comment #23) > (In reply to Jonathan Druart from comment #22) > > Should we really remove a deleted key from the DB table? > > I would flag it as inactive instead, it would permit to keep track of the > > different requests and associate it to a user. > > Disclaimer: This may be a very stupid idea. > > I thought about it too. That would mean an extra column: deleted TINYINT > (1), and it makes sense.