Never really felt the need but I suppose there has always been an updated_when field, so for something that is deleted the updated_when provides the time stamp.
Create an `updated_at` with an on update trigger to set it to NOW(). Your code will never have to explicitly remember to set it.
Go further and create an integer `version` vector clock that gets set to its value plus one. You can see the edit frequency of individual entities and construct a simple key for cache invalidation.
Go further and create an integer `version` vector clock that gets set to its value plus one. You can see the edit frequency of individual entities and construct a simple key for cache invalidation.