# File lib/rubyrep/scan_report_printers/scan_detail_reporter.rb, line 72
    def clear_columns(row)
      case report_mode
      when :full
        row
      when :keys
        row = row[0] if row.kind_of?(Array)
        self.primary_key_names ||= session.left.primary_key_names(self.left_table)
        row.reject {|column, value| !self.primary_key_names.include?(column)}
      when :diff
        self.primary_key_names ||= session.left.primary_key_names(self.left_table)
        if row.kind_of?(Array)
          new_row_array = [{}, {}]
          row[0].each do |column, value|
            if self.primary_key_names.include?(column) or value != row[1][column]
              new_row_array[0][column] = row[0][column]
              new_row_array[1][column] = row[1][column]
            end
          end
          new_row_array
        else
          row
        end
      end
    end