drop_index (KirbyBase::KBTable)

    # File lib/kirbybase.rb, line 2653
        def drop_index(*col_names)
            raise "Do not execute this method in client/server mode!" if \
             @db.client?

            col_names.each do |c|
                raise "Invalid column name: #{c}" unless \
                 @field_names.include?(c)

                raise "recno column index cannot be dropped!" if c == :recno

                raise "Column not indexed: #{c}" if \
                 @field_indexes[@field_names.index(c)].nil?
            end

            @db.engine.drop_index(self, col_names)

            # Need to reinitialize the table instance and associated indexes.

            @db.engine.remove_recno_index(@name)
            @db.engine.remove_indexes(@name)

            update_header_vars
            create_indexes
            create_table_class unless @db.server?
        end