Appengine jdoconfig.xml for local database

Has anyone successfully configured JDO datanucleus default to google app engine to work on a local database? Why am I always getting an error in jdoconfig.xml when I have specified the property "datanucleus.storeManagerType" with value "rdbms." at the end part. I tried googling but seems no luck. Caused by: org.datanucleus.exceptions.NucleusUserException: There is no available StoreManager of type "rdbms". Please make sure you have specified "datanucleus.storeManagerType" correctly and that all relevant plugins are in the CLASSPATH ``` <persistence-manager-factory name="postgresql"> <property name="datanucleus.mapping.Schema" value="jdo"/> <property name="javax.jdo.PersistenceManagerFactoryClass" value="org.datanucleus.store.appengine.jdo.DatastoreJDOPersistenceManagerFactory"/> <property name="datanucleus.ConnectionDriverName" value="org.postgresql.Driver"/> <property name="datanucleus.ConnectionURL" value="jdbc:postgresql://localhost:5432/jdo"/> <property name="datanucleus.ConnectionUserName" value="jdo"/> <property name="datanucleus.ConnectionPassword" value="jdo"/> <property name="datanucleus.appengine.autoCreateDatastoreTxns" value="true"/> <property name="datanucleus.autoStartMechanism" value="None"/> <property name="datanucleus.autoCreateSchema" value="true"/> <property name="datanucleus.validateTables" value="true"/> <property name="datanucleus.validateConstraints" value="true"/> <property name="datanucleus.validateColumns" value="true"/> <property name="datanucleus.DetachAllOnCommit" value="true"/> <property name="datanucleus.maxFetchDepth" value="1"/> <property name="datanucleus.storeManagerType" value="rdbms"/> ``` code for PMF.java ``` private static final PersistenceManagerFactory pmfInstance = JDOHelper.getPersistenceManagerFactory("postgresql"); ```