Configuring StatementCache interceptor in org.apache.sling.datasource, prevents the RDBDocumentStore to correctly start up due to a bug in the StatementCache interceptor (see https://bz.apache.org/bugzilla/show_bug.cgi?id=59850).
Recommended solution is to update the tomcat pool to a fixed version (7.0.71) once it's out. Until that is the case we can
- recommend not to turn on the StatementCache, or
- use a recent Oak version which works around the bug (OAK-4559).