Trans attribute

Question

Hi,
I use CMT.
1. In my EJB method, I simply delete a record from the Oracle database using sql query.Which transaction attribute would be appropriate in this case?
I guess 'NotSupported' is appropriate as I don't have multiple sql queries to delete.
2. Also, in the same page, when I call a single select sql query from my EJB method, I can use 'NotSupported'.
3.When I have a simple insert / update sql query(only insert/update in one table), I can use 'NotSupported'.
4.When I have to insert / update multiple sql queries in my EJB method,other transaction attributes would be appropriate.
Please let me know whether the above are correct.
Thanks in advance,

Answer 1

Hi,
From my own experience the type of transaction attribute you choose does not depend on the number of performed operations, but on other components that expect that operation to succeed. If you don't care if your operations (inserts, updates and deletes) fail or not, then maybe you could do away with transaction processing altogether. On the other hand, if other components (EJBs) require your code to succeed, then use TX attribute of Mandatory (transaction must exist), and start your transaction somewhere else with TX attribute of Required. This way new transaction will be started, and your beans (components) will join it.
I would suggest downloading a copy of "Mastering EJBs" from this location (it's free):
http://www.theserverside.com/books/wiley/masteringEJB/index.tss
Read the chapter on Transactions - in my opinion this is the best book on the subject.
I hope this helps.
Mark