You can specify which Java Persistence API (JPA) persistence provider
to use for each persistence unit in the
file. However, if no persistence provider is specified, the domain-wide
default provider is used.
Changing the default provider does not affect applications that are already deployed. The setting takes effect when the server is restarted or the application is manually redeployed.
For information about using JPA in Oracle WebLogic Server, see "Using Oracle TopLink with Oracle WebLogic Server" in Developing Enterprise JavaBeans for Oracle WebLogic Server.