I have a generic question regarding session management. According to the following posts,

http://sourceforge.net/forum/message.php?msg_id=2814381

session-per-application-transaction is the best and session-per-request is recommended.

Can some experts give an explanation and comparision on the following 8 different patterns -- why one is good and the other one is bad? Especially, why session-per-user-session is bad? What are the problems it will generate?

1. session-per-user-session
2. session-per-application
3. session-per-operation
4. session-per-request
5. session-per-transaction
6. session-per-request-with-multiple-transactions
7. session-per-request-with-detached-objects
8. session-per-application-transaction

Thanks a lot in advance!

Zhan