If there are only reading operations from a database and no other resources hava to be synchronized then it's better not to use transactions in the concerning ejb method. It's not only JTA overhead but also overhead for maintaining the persistence context (if you're using JPA).
Transaction attributes that prevent using transactions are NEVER and NOT_SUPPORTED. But in general it's safer to use NOT_SUPPORTED.
SCJP 5 (98%) - SCBCD 5 (98%)
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