Juan, Many AppServers usually provide a way to tune the pool & cache sizes of entity beans as one technique to limit the number of entity bean instances.
However, this strategy usually gets thrown out of the window when you start accessing a large number of entity bean instances _within_ the scope of a single transaction (say the results of a finder or an ejbSelect method). This at least holds true of most AppServers I know of. (bar us ;) Given that your AppServer cannot be a memory hog or run out of memory when you access a large number of entity bean instances in a single transaction, there must be some strategy in place to limit the number of entity instances in memory. And a (potentially) long running transaction should not really impact other concurrent transactions running within the EJB Container. The paper at: http://community.borland.com/article/0,1410,29074,00.html should explain our strategy. It also explains the various Transaction Commit Options defined in the EJB spec as implemented by a vendor. The transaction commit options also translate to caching strategies implemented by a vendor when using entity beans. Unfortunately, the commit options defined in the spec [and their association with caching strategies] still remains a source of confusion (or ignorance) for many EJB developers. -krish > -----Original Message----- > From: A mailing list for Enterprise JavaBeans development > [mailto:[EMAIL PROTECTED]] On Behalf Of Juan Pablo Lorandi > Sent: 12 December 2002 11:54 > To: [EMAIL PROTECTED] > Subject: Re: Why we need entity beans????????? > > > Hola!!! Saludos desde Rosario. > > No, it doesn't mean that. Usually, Application Servers are > smart enough > to load EB to memory lazily. That means, if you're not using > more than N > records at a time, then only N beans are loaded. > > Juan Pablo Lorandi > Chief Software Architect > Code Foundry Ltd. > [EMAIL PROTECTED] > > Barberstown, Straffan, Co. Kildare, Ireland. > Tel: +353-1-6012050 Fax: +353-1-6012051 > Mobile: +353-86-2157900 > www.codefoundry.com > > > > -----Original Message----- > > From: A mailing list for Enterprise JavaBeans development > > [mailto:[EMAIL PROTECTED]] On Behalf Of Emilio > Gustavo Orme�o > > Sent: Wednesday, December 11, 2002 11:31 AM > > To: [EMAIL PROTECTED] > > Subject: Re: Why we need entity beans????????? > > > > > > Does it mind that, if I had a two millions records table, > > I'll need a lot of memory to support each instance of the > > entity bean ? > > > > Satyanarayana_Godavarti escribi�: > > > > >Hi Murali, > > > > > >Session bean meant for your business process. It can do a > > simple thing > > >like tax calculation or connecting to another bean etc. > The session > > >beans are verbs of your application. You cannot handle transaction > > >management through session bean. At the best you can get the > > data from > > >the database but you cannot do update existing record or > > adding a new > > >record in the database. > > > > > >The entity beans are nouns of your application. These are your > > >persistence objects. It represents your permanent data. > Entity beans > > >are capable of handling the transactions. Each table in your > > database > > >represents one entity bean and each instance of a bean > represents a > > >record in that table. > > > > > >You can use session beans for transaction but you have to go for > > >Synchronized session beans. > > > > > >Regards, > > >Murthy > > > > > > > > >-----Original Message----- > > >From: Murali Mohan [mailto:[EMAIL PROTECTED]] > > >Sent: Wednesday, December 11, 2002 11:06 AM > > >To: [EMAIL PROTECTED] > > >Subject: Why we need entity beans????????? > > > > > > > > >Hi all, > > > > > >I have a basic doubt about entity beans??? > > >Why we need it????From sessionBeans also we can connect to > DB and do > > >all the operations. > > > > > >Why we need entity beans?????????What are extra uses??????? > > > > > >Thanks, > > >Mohan > > > > > >============================================================= > > ========== > > >==== > > >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". > > >************************************************************* > > ************* > > >This email (including any attachments) is intended for the > > sole use of the > > >intended recipient/s and may contain material that is > > CONFIDENTIAL AND > > >PRIVATE COMPANY INFORMATION. Any review or reliance by > > others or copying or > > >distribution or forwarding of any or all of the contents in > > this message is > > >STRICTLY PROHIBITED. If you are not the intended recipient, > > please contact > > >the sender by email and delete all copies; your cooperation > > in this regard > > >is appreciated. > > >************************************************************* > > ************* > > > > > >============================================================= > > ========== > > >==== > > >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". > > > > > > > > > > > > > -- > > Emilio Gustavo Orme�o Sarmiento > > Licenciado en Informatica > > [EMAIL PROTECTED] > > Julio A. Roca Norte 637 > > San Juan - Capital > > Tel. Par. 054 0264 4201514 > > Tel. 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