jndi-name

only one 

Specifies the absolute jndi-name of a JDBC resource.

default-resource-principal

zero or one 

Specifies the default runtime bindings of a resource reference. 

property (with subelements)

zero or more 

Specifies a property name and value. Used to configure PersistenceManagerFactory properties.

create-tables-at-deploy

zero or one 

If true, specifies that database tables are created for beans that are automatically mapped by the EJB container.

drop-tables-at-undeploy

zero or one 

If true, specifies that database tables that were automatically created when the bean(s) were last deployed are dropped when the bean(s) are undeployed.

database-vendor-name

zero or one 

Specifies the name of the database vendor for which tables can be created. 

schema-generator-properties

zero or one 

Specifies field-specific type mappings and allows you to set the use-unique-table-names property.