rename_column (KirbyBase::KBTable)

    # File lib/kirbybase.rb, line 2458
        def rename_column(old_col_name, new_col_name)
            raise "Do not execute this method in client/server mode!" if \
             @db.client?

            raise "Cannot rename recno column!" if old_col_name == :recno
            raise "Cannot give column name of recno!" if new_col_name == :recno

           raise 'Invalid column name to rename: ' % old_col_name unless \
             @field_names.include?(old_col_name)

           raise 'New column name already exists: ' % new_col_name if \
             @field_names.include?(new_col_name)

            @db.engine.rename_column(self, old_col_name, new_col_name)

            # 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