docs: def _clean_up_columns(
              self):
          """clean up columns of the NED table
  
          .. todo ::
  
              - update key arguments values and definitions with defaults
              - update return values and definitions
              - update usage examples and text
              - update docstring text
              - check sublime snippet exists
              - clip any useful text to docs mindmap
              - regenerate the docs and check redendering of this docstring
          """
          self.log.debug('starting the ``_clean_up_columns`` method')
  
          tableName = self.dbTableName
  
          print "cleaning up %(tableName)s columns" % locals()
  
          sqlQuery = u"""
                  set sql_mode="STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION";
              """ % locals()
          writequery(
              log=self.log,
              sqlQuery=sqlQuery,
              dbConn=self.cataloguesDbConn,
          )
  
          sqlQuery = u"""
                  update %(tableName)s set dist_mod_err = null where dist_mod_err = 0;
                  update %(tableName)s set dist_in_ned_flag = null where dist_in_ned_flag = "";
                  update %(tableName)s set notes = null where notes = "";
                  update %(tableName)s set redshift = null where redshift = 0;
                  update %(tableName)s set dist_derived_from_sn = null where dist_derived_from_sn = "";
                  update %(tableName)s set hubble_const = null where hubble_const = 0;
                  update %(tableName)s set lmc_mod = null where lmc_mod = 0;
                  update %(tableName)s set master_row = 0;
                  update %(tableName)s set master_row = 1 where primaryId in (select * from (select distinct primaryId from %(tableName)s group by galaxy_index_id) as alias);
              """ % locals()
          writequery(
              log=self.log,
              sqlQuery=sqlQuery,
              dbConn=self.cataloguesDbConn,
          )
  
          self.log.debug('completed the ``_clean_up_columns`` method')
          return None