Thanks, marina. Yes, the 'MYAPP' schema already exists in myappdb, and that schema can be accessed from outside of the application server using the url noted in the persistence.xml file ('jdbc:derby://localhost:1527/myappdb').
For some reason, the application server uses an alternate url ('jdbc:derby://localhost:1527/sun-appserv-samples;;create=true') to access the database/schema.
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