In Red Hat JBoss Data Grid, JPA Cache Store does not work with Oracle12c and Postgres Plus 9 as Hibernate, an internal dependency of JPA Cache Store, is not able to determine which dialect to use for communication with the database. This is a known issue in JBoss Data Grid 6.4. As a workaround for this issue, specify the Hibernate dialect directly by adding the following element in the <filename>persistence.xml</filename> file: <programlisting language="XML"><![CDATA[<property name="hibernate.dialect" value="${hibernate.dialect}" />]]></programlisting> Set <replaceable>${hibernate.dialect}</replaceable> to <literal>org.hibernate.dialect.Oracle10gDialect</literal> or <literal>org.hibernate.dialect.PostgresPlusDialect</literal> for Oracle12c or Postgres Plus 9 respectively.