[AccessD] How does Access locking work

 And that it's exactly.

 I have the white paper here somewhere written by Kevin Collins that
describes the locking (even includes a DB lock utility you can use to poll
locks).  However it was never updated for JET 4.0 and record level locking.
How that works has never been described anywhere.  It's also incomplete in
that it describes all the locks for 3.5, but locking in JET 4.0 was changed
(besides the record locking), so the types of locks and when they are placed
are different.

 What's your goal?

Jim. 

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby
Sent: Thursday, September 15, 2011 06:23 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] How does Access locking work

It does make sense and that is what I am talking about.

John W. Colby
www.ColbyConsulting.com

On 9/15/2011 1:51 AM, Drew Wutka wrote:
> I think I have the old Jet white paper somewhere.  But basically Jet
> would 'lock' the .ldb file where it needed to lock the .mdb.  So the
> .mdb would never be locked (allowing for multiple edits), and the lock
> on the .mdb would be actually on the .ldb file.
>
> So say the .mdb was 100 megs.  And it needed to lock the 50th megabyte,
> the .ldb file was always small (I think it was 64 bits per user, up to
> 255 users), so it would never reach the 50 meg size, but the 'lock'
> would be placed on the 'virtual' 50 meg point of the .ldb.
>
> Make sense?
>
> Drew
>
> -----Original Message-----
> From: accessd-bounces at databaseadvisors.com
> [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby
> Sent: Wednesday, September 14, 2011 9:47 PM
> To: Access Developers discussion and problem solving
> Subject: [AccessD] How does Access locking work
>
> I need to find documentation about the actual locking mechanism for
> Access.  I vaguely remember something about Jet using a file, and (IIRC)
> applying system locks to pieces out past the end of that file.  It is
> all very old memories and I am not finding anything "real" about the
> actual details.
>
> Anyone know what it was I read so long ago?
>
> --
> John W. Colby
> www.ColbyConsulting.com
> --
> AccessD mailing list
> AccessD at databaseadvisors.com
> http://databaseadvisors.com/mailman/listinfo/accessd
> Website: http://www.databaseadvisors.com
> The information contained in this transmission is intended only for the
person or entity
> to which it is addressed and may contain II-VI Proprietary and/or II-VI
Business
> Sensitive material. If you are not the intended recipient, please contact
the sender
> immediately and destroy the material in its entirety, whether electronic
or hard copy.
> You are notified that any review, retransmission, copying, disclosure,
dissemination,
> or other use of, or taking of any action in reliance upon this information
by persons
> or entities other than the intended recipient is prohibited.
>
>
-- 
AccessD mailing list
AccessD at databaseadvisors.com
http://databaseadvisors.com/mailman/listinfo/accessd
Website: http://www.databaseadvisors.com