no-tx-datasource vs local-tx-datasource

[shapirod]

Hello all,

If an EJB is using bean managed transactions, and there is no UserTranscation in effect, is there any difference in overhead for DB reads between using a no-tx-datasource vs local-tx-datasource?

Thanks,
Daniel Shapiro
Agilquest, Inc.

[vickyk]

"shapirod" wrote:
Hello all,

If an EJB is using bean managed transactions, and there is no UserTranscation in effect, is there any difference in overhead for DB reads between using a no-tx-datasource vs local-tx-datasource?

Thanks,
Daniel Shapiro
Agilquest, Inc.

There would not be any difference if there is no ongoing transaction.
If there is an on going transaction then some time will be taken in resource enlistment in TransactionManager , the associated TM implementation would optimize the 2PC(two phase protocol) to just a commit call when the TM realizes that there in only one participant in TX .
Again the 2PC optimizations is not mandated by JCA specs , the TM should do it .

[shapirod]

Thank you! That's very helpful.