> I am now researching the concurrency control methodology in Firebird,
> But do not know where to go?
>
> Is Firebird using a Lock-based control or timestamp-based control, or
> others?
>
> Which part of the source file I can refernce??

Reading this would be a start:
http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_bill_todd_mga

Paul