try{
XDocumentSubStorageSupplier doc = (XDocumentSubStorageSupplier)UnoRuntime.queryInterface(XDocumentSubStorageSupplier.class,ds);
XStorage stor = doc.getDocumentSubStorage("database",4);
try{
if ( stor.isStreamElement("db.log") )
stor.removeElement("db.log");
} catch(Exception e){}
try{
if ( stor.isStreamElement("db.properties") )
stor.removeElement("db.properties");
} catch(Exception e){}