rename_column

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 1051
      def rename_column(table_name, column_name, new_column_name)
        clear_cache!
        execute "ALTER TABLE #{quote_table_name(table_name)} RENAME COLUMN #{quote_column_name(column_name)} TO #{quote_column_name(new_column_name)}"
      end