@TransactionAttribute(TransactionAttributeType.REQUIRED) public void someMethod(...) { // obtain con1 and con2 connection objects con1 = ...; con2 = ...; stmt1 = con1.createStatement(); stmt2 = con2.createStatement(); // // Perform some updates on con1 and con2. The container // automatically enlists con1 and con2 with the container- // managed transaction. // } As we have specified TransactionAttributeType.REQUIRED, container will start a transaction (i guess on a Connection) Q- a) Container will start transaction on which Connection (database) Object? From where it obtains information about my database ? In other words does container uses JTA (Distributed transaction manager layer), from where it obtains info regarding my databses, user password, url etc.. Q- b) What does the statement means "The container automatically enlists con1 and con2 with the container-manager transaction"? View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4258541#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...