def __init__( self, fn, mode ):    

    Frontend.__init__( self, fn, mode );

    self._kdbfn = None;
    self._kdb = None;

    self._ldbdn = None;
    self._ldb = None;

    self._len_c = None;
    self._len_b = None;
    self._len_x = None;

    self._ic = None;
    self._icbp = None;

    self._needs_initialization = True;

    self._core_dims = set();
    self._satellite_dims = set();
    self._removed_dims = set();

    self._remove_c = set();
    self._remove_b = set();
    self._remove_x = set();

    self.bypass_c = False;
    self.bypass_b = False;
    self.bypass_x = False;
  def __init__( self, fn, mode ):

    Frontend.__init__( self, fn, mode );
    self._max_rows = 50000;

    self._dbs = {};
    self._dbdirs = [];
  def __init__( self, fn, mode ):

    Frontend.__init__( self, fn, mode );
    self._max_rows = 100000;
    
    self._stats = {};
  def __init__( self, fn, mode ):

    Frontend.__init__( self, fn, mode );
    self._max_rows = 100000;

    self._data = [];