[AccessD] corrupt database - backup rather out-dated.

Hi Gary:

In my formative years, I hacked many file formats but then there was no other way to recover from a serious data crash.

All I know is that you can delete certain index files if the MDB becomes corrupted using a Hex editor by just setting the header or link bytes...did this many years ago. It you created a blank database, added some forms, tables, keys and indexes, first scanned the file with the sector editor then deleted some objects and checked what happens. If you work through the MDB file it wouldn't be long before you start to recognize certain patterns. (Many years ago, I built my own hex/decimal editor, in VB, for just such a purpose and offered to anyone in the DBA list who was interested...I have since lost it...) An MDB file is good for that, as it never deletes anything, just links around deleted objects, until compressed. Everything is still in there...and I would bet there are just a couple files with their headers that are scrambled.

No, I am not volunteering as I know what a time-consuming drudge this could be...been there, done that and now it is time for the smart young guys. ;-) If someone is interested in taking up the torch, I will take a serious look for the editor but there are many free such editors that have just as many features and run more stable and faster.  

Jim     

----- Original Message -----
From: "Gary Kjos" <garykjos at gmail.com>
To: "Access Developers discussion and problem solving" <accessd at databaseadvisors.com>
Sent: Monday, June 2, 2014 1:58:22 PM
Subject: Re: [AccessD] corrupt database - backup rather out-dated.

Years ago we had a discussion here about using a hex editor on an Access
MDB file and copying parts of a working MDB file into a corrupted one in
order to make it good enough to be able to be opened and for code or
something to be extracted. It was a LONG time ago though and I don't recall
if it was actually successful or just a theoretical discussion.

GK


On Mon, Jun 2, 2014 at 3:44 PM, Bill Benson <bensonforums at gmail.com> wrote:

> I am happy to say that I did separate the data tables the program. Much of
> the advice given here is something that I already follow. However, it is
> true that if I had made a backup just some hours before that I would be in
> better shape than I am.
>
> I guess this could have been a thread about how to prevent the downside of
> this happening in the future. There are many such threads. However mainly
> this was a thread about a corrupt database and whether it could be fixed.
> Thanks all of those who offered help in this regard.
> On Jun 2, 2014 2:14 PM, "Gary Kjos" <garykjos at gmail.com> wrote:
>
> > That is certainly a good idea once you have the thing done but it can be
> a
> > pain during development as you may be adding fields and indexes and such
> > and having the data split up front can add work as you would need to
> > refresh links many times potentially.
> >
> > At least that is how I remember it from my develop for others days.
> >
> > GK
> >
> >
> > On Mon, Jun 2, 2014 at 1:06 PM, Jim Lawrence <accessd at shaw.ca> wrote:
> >
> > > Hi Gary:
> > >
> > > I would also add that it is a good idea to separate the actual data
> > tables
> > > from the rest of the application.
> > >
> > > Jim
> > >
> > >
> > --
>


-- 
Gary Kjos
garykjos at gmail.com
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