Subject Re: Shred records
Author Adam
--- In, Helen Borrie <helebor@...> wrote:
> At 07:54 PM 28/04/2007, you wrote:
> >I was actually trying to find the answer to my question by researching
> >if it's possible to retrieve deleted records. As you say there are
> >some ways achieving this with tools such as IBundelete or hexeditors.
> >Can I conclude that the Nature of Firbird makes it impossible to
> >recover deleted or updated records once the database performs a SWEEP?
> To all intents and purposes, yes.

Hi Helen,

I was not aware that Firebird deliberately blanked out the piece of
the file containing the deleted stub during a sweep. I had just
assumed it just marked it as space that could be reused (like most
DBMS and like most file systems), meaning someone with a hex editor
who knows what they are doing could locate data providing it had not
yet been overwritten. Am I wrong?

To securely shred deleted records in a database, I would back it up,
then restore it, then use a secure deletion tool to delete the old
database. Of course I imagine there may still be some traces of data
in virtual memory or in some sort file.