# File lib/active_record/connection_adapters/postgresql_adapter.rb, line 1045
      def change_column(table_name, column_name, type, options = {})
        clear_cache!
        quoted_table_name = quote_table_name(table_name)

        execute "ALTER TABLE #{quoted_table_name} ALTER COLUMN #{quote_column_name(column_name)} TYPE #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}"

        change_column_default(table_name, column_name, options[:default]) if options_include_default?(options)
        change_column_null(table_name, column_name, options[:null], options[:default]) if options.key?(:null)
      end