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Thread How to avoid environmental locks on DBISAM files, Vista etc.
Sun, Nov 25 2007 5:48 PMPermanent Link

Sam Jones
We are having an increasing number of problems in the field with PC environments attacking
the DBISAM files.

First there was the .blb itis issue, discussed here:
http://www.elevatesoft.com/scripts/newsgrp.dll?action=searchopenmsg&group=5&msg=59816&keywords=deleting*%20blb*#msg59816
among other places.

Now I am seeing on a few Vista machines, that some of the DBISAM table elements are
locked... by something, and DBISAM cannot open the table. So far I have uninstalled: Anti
virus apps and Google Desktop. No help yet. I am seeing these issues on stand alone PCs,
no networking of the DBISAM db.


Any one out there seeing this kind of problem?

I would like to enhance the DBISAM engine to check its environment in some way. E.g.

 -File abc.blb is missing
 -File dfg is locked by process X, exe name Y

Is there anything of this ilk out there?


Is there some straight way to put the entire DBISAM dir into a single file, structured
storage or such?

Anything that can give us a simple thumbs up or down to effect "The whole system is here
and ready" Instead of: DBISAM 11013 unable to access table....


Thank you!
Sun, Nov 25 2007 7:23 PMPermanent Link

Eryk Bottomley
Sam,

> Now I am seeing on a few Vista machines, that some of the DBISAM table elements are
> locked... by something, and DBISAM cannot open the table. So far I have uninstalled: Anti
> virus apps and Google Desktop. No help yet. I am seeing these issues on stand alone PCs,
> no networking of the DBISAM db.
>
>
> Any one out there seeing this kind of problem?


At a guess, something to do with Vista trying to replicate files in the
background to 'protect' against unauthorised modifications. I haven't
actually seen this happen, but then we don't use Vista (and refuse to
support anyone who tries to run our stuff on it).

> I would like to enhance the DBISAM engine to check its environment in some way. E.g.
>
>   -File abc.blb is missing

Assuming you know in advance what tables are supposed to be there then
the easiest check is probably to run through the list opening (and then
closing) a TFileStream on each file prior to opening any tables/queries.
This will identify any missing files precisely, detect any locks that
shouldn't be there and also takes DBISAM out of the equation entirely
allowing you to point the finger unequivocally at external factors.

>   -File dfg is locked by process X, exe name Y
>
> Is there anything of this ilk out there?

Not programmatically (at least not without a LOT of low level work). If
you can use a utility then the following should help:

http://www.microsoft.com/technet/sysinternals/FileAndDisk/processmonitor.mspx

> Is there some straight way to put the entire DBISAM dir into a single file, structured
> storage or such?

No. (More precisely, "yes" ...but only as a static backup - you can't
access the tables when they are in that form)

Eryk
Mon, Nov 26 2007 5:08 PMPermanent Link

Tim Young [Elevate Software]

Elevate Software, Inc.

Avatar

Email timyoung@elevatesoft.com

Sam,

<< Now I am seeing on a few Vista machines, that some of the DBISAM table
elements are locked... by something, and DBISAM cannot open the table. So
far I have uninstalled: Anti virus apps and Google Desktop. No help yet. I
am seeing these issues on stand alone PCs, no networking of the DBISAM db.
>>

These types of issues are usually found on single-user machines.  Are you
storing any DBISAM tables in (possibly) virtualized folders in Vista such as
Program Files ?  If you could give me some more information on your
environment and configuration, I can do some more digging into the issue.

--
Tim Young
Elevate Software
www.elevatesoft.com

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