Note that the API's are a moving target and advantages and disadvantages change from release to release. You might first read the faq page (http://jakarta.apache.org/ojb/faq.html). This page says,
The OJB ODMG implementation uses the PB as its persistence kernel. But it provides much more functionality to the application developer. ODMG is a full fledged API for Object Persistence, including: OQL Query interface real Object Transactions A Locking Mechanism for management of concurrent threads (apps) accessing the same objects predefined persistent capable Collections and Hashtables Note that a few people dislike the current ODMG OQL Query interface and prefer PB's Query api. But the way PB/ODMG is implemented you can use PB query with ODMG's api. Note also that locking a described above is totally independent of the RDBMS locking. This is something I am currently struggling with because my app's RDBMS is used by lots of other applications and the ODMG object locking only works if every app using the RDBMS is using ODMG. I probably should add that this is my current understanding and I could be wrong. Like I said, I am currently struggling with these issues. I just don't have a good feel for the issues with using ODMG in a mixed environment where all the other apps are using standard optimistic locking. JDO is not finished so depending on your timing that may eliminate this api. As far as PB vs OJB you might review some questions I've raised (search on "ODMG and locking" and "PersistenceBroker or ODMG"). Jeff -----Original Message----- From: Marian Skalsky [mailto:[EMAIL PROTECTED]] Sent: Friday, October 11, 2002 3:57 AM To: [EMAIL PROTECTED] Subject: Persistence broker vs. ODMG vs. JDO with OJB Hi there! I'm a newbie in OJB and I've got, aka old chestnut question, but I was unable to find the answer on the mailing list archive. I need some persistent layer for my future web project based on struts. From these (Torque, Hybernate and OJB) I decided for OJB. Now I think about which API to choose. As I worked a bit with EJB before (but it is too robust for this project) I lean towards to use of JDO API. JDO seems to me to be very close to EJB and concerning to discussion at http://www2.theserverside.com/discussion/thread.jsp?thread_id=771#57149 I think it should fit my needs. And what I wanna ask: Can somebody experienced name advantages and disadvantages of each API aproach (Persistence broker, ODMG, JDO) (or provide the link where to find answers)? I will appreciate it very much! Thx in advance. $kala. --- Odch?dzaj?ca spr?va neobsahuje v?rusy. Skontrolovan? antiv?rusov?m syst?mom AVG (http://www.grisoft.cz). Verzia: 6.0.394 / V?rusov? datab?za: 224 - d?tum vydania: 4. 10. 2002 -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
