--- In Firebird-Java@yahoogroups.com, Mark Rotteveel <mark@...> wrote:

>
> On 18-5-2013 13:20, hugo.larson wrote:
> > Here is another exception:
> >
> > Caused by: org.firebirdsql.gds.GDSException: Error reading data from the connection.
> > null
> > at org.firebirdsql.gds.impl.wire.AbstractJavaGDSImpl.receiveResponse(Unknown Source)
> > at org.firebirdsql.gds.impl.wire.AbstractJavaGDSImpl.iscStartTransaction(Unknown Source)
> > at org.firebirdsql.gds.impl.GDSHelper.startTransaction(Unknown Source)
> > at org.firebirdsql.jca.FBManagedConnection.findIscTrHandle(Unknown Source)
> > at org.firebirdsql.jca.FBManagedConnection.internalStart(Unknown Source)
> > at org.firebirdsql.jca.FBLocalTransaction.internalBegin(Unknown Source)
> > at org.firebirdsql.jca.FBLocalTransaction.begin(Unknown Source)
> > ... 66 more
>
> This is triggered by an IOException as well, unfortunately I didn't
> include it for this Exception. However, this IOException should be
> logged if you have logging setup and enabled on debug level.
>
> The stacktrace you sent earlier was with iscStartTransaction as well,
> but then during the send of the transaction start operation, now it is
> failing after the operation has been sent, but during the receive of the
> response from the server. Is there anything in the logs of Firebird?
>
> I will review the transaction code. Do you by any chance use a custom
> transaction parameter buffer or transaction configuration?
>
> Mark
> --
> Mark Rotteveel
>

I'm just using plain DataExpress components without any transaction. And these Exceptions occurs on read operations.

And seems that default transactionisolation is READ_COMMITED. Do you think its a good idea to experiment with this parameter?