Subject Re: FireBird locks
Author chris_delphi
--- In firebird-support@yahoogroups.com, "Ann W. Harrison"
<aharrison@i...> wrote:
>
> chris_delphi wrote:
> >
> > We have found a way to simpify and explain the bug though.
> >
> > So it looks to us as if our client app is trying to grab a
writeable
> > dataset rather than read only.
>
> There's no such thing as a writable data set in Firebird, unless
> you used SELECT ...FOR UPDATE WITH LOCK which seems unlikely.
>
> What it seems like is that the client is running a read committed
> transaction with the options "no record versions" and "wait".
> Since there's an uncommitted version, which the client can't see,
> it waits.
>
> > n.b. as a test if we run the same query in IB Expert while the
server
> > is paused it will return the dataset and not lock.
>
> IB Expert is using different options - specifically it allows
> the client to read the newest committed version rather than waiting
> for the uncommitted version.
>
> Regards,
>
> Ann
>

Ann
Thank you for your reply, I think that is a concise and correct
description of the problem.

I'm not sure how/why the Firebird ODBC driver we where using was not
picking up those settings (Assuming we where setting them correctly
and I think we were) but when we switched to Easysoft ODBC driver the
problems stopped. So at least we can continue on with development. If
I ever get five minutes I'll see if I work out exactly what the
problem was.

Regards

Chris