On Sun, 15 Jan 2012 20:37:37 -0000, "richwiz11"
<richard.crowle@...> wrote:

> Hi, I need a way of logging or protecting data from being deleted by a
> user.
>
> I work for a POS (point of sale) company, each user "shop" would have a
> local firebird db running. We are entering into a new market where
> regulation states we have to protect our system from tax evasion (where
> possible)

Next to the suggestions given by others, you could also considering adding
a hash or (better yet) a cryptographic message digest of all other records
fields to every record (the hash or message digest would need to be
calculated by your application, not by the database!). This can be used to
identify tampered records. De keep in mind that a determined person can -
with some trouble - still produce a valid hash or message digest if he has
access to the application.

Mark