Thanx very much for the help Roman, lets see if I can be more specific,

> Do you synchronize on Connection object? What about transaction control?

I built a class called Database wich encapsulates a JBird Connection. When I
call database.connect(), it is created an auto-committed Connection. The
method used for updates is called execUpdate and is synchorinzed. So, I
create an Database object, call the method connect and start the threads.
Each thread will then call the execUpdate method.

> Check the output of executeUpdate() method (it returns you information
> about affected rows, in your case it should be 1). If it is correct,
> check the transaction management, maybe you rolled the transaction back.

I made a step-by-step execution and the output of executeUpdate is 1 just as
you said. The connection is auto-committed, as I said before. Do you know if
an auto-committed transaction can be rolled back? If yes, is there any way
of discovering if it occurred and why?

>
> Best regards,
> Roman

Regards,

Diego Moreira da Rosa

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