Can I use a one-phase commit if my WebLogic JMS JDBC store is on the same database for which I am doing other database work?
A. No. WebLogic JMS is its own resource manager. That is JMS itself implements XAResource and handles the transactions without depending on the database (even when the messages are stored in the database). That means whenever you are using JMS and a database (even if it is the same database as the JMS messages are stored) then it is 2PC. You may find it will aid performance if you ensure the connection pool used for the database work exists on the same server as the JMS queue—the transaction will still be two-phase, but it will be handled with less network overhead. Another performance boost might be achieved by using JMS file stores rather than JMS JDBC stores.
