The class JdbcAdapterInternalService has a bug(I think) in the method select_p that prevents a XQuery select statement from being recognized as a select statement, falling always to the executeUpdate method, thus failing. The query has the following format: "xquery declare default element namespace "http://private";declare namespace h="http://private/ns1";declare namespace hi="http://private/ns2"; <Private> { for $h in db2-fn:sqlquery("SELECT xmldata FROM..." Not sure if it's the best solution, but it's working so far on our project.