With nondurable identity your objects will not have a unique identity in the datastore. This type of identity is typically for log files, history files etc where you aren't going to access the object by key, but instead by a different parameter. In the datastore the table will typically not have a primary key. To specify that a class is to use nondurable identity, you would add the following to the MetaData for the class.

<class name="MyClass" identity-type="nondurable">
...
</class>

JPOX doesn't currently support this type of identity for persistence