Hi,

>that I will use 510 bytes (to save old and new value)...

Why store both the old and the new values? You could store a copy of the database before auditing begins and only record the new values. Equally you could choose to only store the old values since the new ones, by definition, will be the current database values.

Either way if these are stored with table and field information then you will have suffucient information to either roll back the current database or roll forward from the original copy.

Regards,
Viv