The J2EE spec states that you are not allowed to call the setTransactionIsolation method.
/Johan citerar SAMINATHAN <[EMAIL PROTECTED]>: > Dear Mr Krishnan > > Thanks for your reply first.But in our case CMP is ruled > out.Since we had a very complex parent--child relationship in our > application, we did not have any other option other than opting BMP (EJB > 1.1 > spec) . > Any way we are in the verge of completing our project, so i wanted to know > by setting setTransactionIsolation() in my entity can i avert the > concurrency or not?.Since i tried to do that but i don't know how to > simulate the concurrent access.Hence am not able to verify. > > Thanks and Regards > > Saminathan. > > > ----- Original Message ----- > From: "Krishnan Subramanian" <[EMAIL PROTECTED]> > To: "SAMINATHAN" <[EMAIL PROTECTED]> > Sent: Monday, March 11, 2002 2:58 PM > Subject: RE: Re: basic transaction management and isolation level question > > > > Saminathan, > > > > In the case of BMP, you (that is, the developer) is responsible > > for managing concurrency and consistency of data. So, you would > > have to take the above into account if you want to write 'bullet > > proof' BMPs that are safe when accessed concurrently by multiple > > transactions. > > > > But in the case of CMP, it is as simple as turning on a flag (in > > the deployment descriptor) to tell the Container what kind of > > strategy to use. (For example you could tell it to use verified > > updates and/or you could tell it to use Oracle's syntaxt "Select > > ... For Update" for locking etc. And in the case of BMP, you'd > > have to handcode all these which takes time & effort. EJBs are > > supposed to aid developers in developing business components and > > not let the developers worry about lower level system issues such > > as persistence mechanisms and strategies. Also, if you handcode > > these - as in the case of BMP - you'd probably have to recode when > > you switch databases to one that supports a different locking > > strategy). > > > > It is best to avoid BMP. The performance of CMP is almost 2x times > > faster than its BMP counterpart. CMP code is also cleaner, more > > readable and easier to maintain & port than BMP. The Container also > > can perform optimizations - simply because it has control of when > > and what SQL code to execute (or not to execute) . But if you write > > BMP, then the Container has no control - and hence the possiblity > > of optimizing BMP code (by the Container) is reduced greatly. > > > > -krish > > > > > -----Original Message----- > > > From: SAMINATHAN [mailto:[EMAIL PROTECTED]] > > > Sent: Saturday, March 09, 2002 5:52 AM > > > To: Krishnan Subramanian > > > Subject: Re: Re: basic transaction management and isolation level > > > question > > > > > > > > > Hi Krish > > > > > > I got a chance to go thru your design pattern white paper from > > > Borlando Site. > > > The very interesting aspect in that how Borlando Managing the > Concurrency > > > issue, that's fantastic in case of CMP. > > > But i would like to know how your server will behave if it is a > BMP.Will > it > > > take care by iteself. I guess no.If it is not > > > do i need to set any transaction level in SLSB or Entity. > > > > > > I am eagrly waiting for your Reply. > > > > > > Thanks and Regards > > > B.Saminathan, > > > System Analyst, > > > House of Code pvt(I) Ltd, > > > Bombay. > > ======================================================================== === > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff EJB-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". > > =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
