After quite some years of experience with DBISAM V3, I keep noticing
that users who run my app on a system that has two apps accessing the
same DB simultaneously, suffer more data corruption than others.

My questions:

1) is there anything I can do in V3 to avoid this?

2) would V4 solve these issues?

Thanks,
Dom

Additional question:

Does a RepairTable imply a LockTable? Ie. do all apps suspend access to
the table being repaired by another app?

Dominique


RepairTable requires exclusive access to the table.

Roy Lambert [Team Elevate]

Dominique


1. Do you have any information about what the corruption is and what's causing it, what the PC configuration & OS is?

2. Try FlushBuffers after posting data. That should mean its written to disk and safe.

Roy Lambert [Team Elevate]

Roy Lambert wrote:
> 1. Do you have any information about what the corruption is and
> what's causing it, what the PC configuration & OS is?

No, it varies. And PC and OS too.

> 2. Try FlushBuffers after posting data. That should mean its written
> to disk and safe.

Yes, that's what I'm doing. I'm guessing a RepairTable while another
app is accessing the data might be one of the reasons.

"Dominique Willems" <dominique.willems@gmail.com> wrote in message
news:7610B6DA-BDFF-438A-9E65-4DC1A7734F1D@news.elevatesoft.com...
>
> Yes, that's what I'm doing. I'm guessing a RepairTable while another
> app is accessing the data might be one of the reasons.

The repair will not start if another app is accessing the table (at least in
the current version of DBISAM). Flushbuffers and such are only useful if you
suspect hardware problems, or if the data is absolutely critical.

As far as your program corrupting the data, it is possible. Most cases I've
had have been caused by multi-row updates not wrapped in a transaction.

Robert

Robert K wrote:
> The repair will not start if another app is accessing the table (at
> least in the current version of DBISAM).

Is this also the case in version 3? Tim?

"Dominique Willems" <dominique.willems@gmail.com> wrote in message
news:52E82E91-9961-45A3-A8F3-08E2CA1A2FEA@news.elevatesoft.com...
> Robert K wrote:
>> The repair will not start if another app is accessing the table (at
>> least in the current version of DBISAM).
>
> Is this also the case in version 3? Tim?

Try with DBSYS, open the table and then try to do a repair.

R

Dominique


>> The repair will not start if another app is accessing the table (at
>> least in the current version of DBISAM).
>
>Is this also the case in version 3? Tim?

I'm pretty sure is was that way back in V2 as well. Repairing like optimising is something that can not be done with the table being modified at the same time.

Roy Lambert [Team Elevate]

Roy Lambert wrote:
> Repairing like
> optimising is something that can not be done with the table being
> modified at the same time.

Can or won't?