Commit b484f167 authored by Simon Charette's avatar Simon Charette
Browse files

Fixed #26712 -- Avoided unnecessary SET TIMEZONE queries on PostgreSQL. 

A change of the USE_TZ or TIME_ZONE settings doesn't necessarily require a
change to the active connections' timezones.
parent 6a316423

django/db/backends/base/base.py

+7 −0
Original line number Diff line number Diff line
@@ -88,6 +88,13 @@ class BaseDatabaseWrapper(object): 
        # is called?

        self.run_commit_hooks_on_set_autocommit_on = False



    def ensure_timezone(self):

        """

        Ensure the connection's timezone is set to `self.timezone_name` and

        return whether it changed or not.

        """

        return False



    @cached_property

    def timezone(self):

        """

django/db/backends/postgresql/base.py

+12 −8
Original line number Diff line number Diff line
@@ -192,17 +192,21 @@ class DatabaseWrapper(BaseDatabaseWrapper): 


        return connection



    def ensure_timezone(self):

        self.ensure_connection()

        conn_timezone_name = self.connection.get_parameter_status('TimeZone')

        timezone_name = self.timezone_name

        if timezone_name and conn_timezone_name != timezone_name:

            with self.connection.cursor() as cursor:

                cursor.execute(self.ops.set_time_zone_sql(), [timezone_name])

            return True

        return False



    def init_connection_state(self):

        self.connection.set_client_encoding('UTF8')



        conn_timezone_name = self.connection.get_parameter_status('TimeZone')



        if self.timezone_name and conn_timezone_name != self.timezone_name:

            cursor = self.connection.cursor()

            try:

                cursor.execute(self.ops.set_time_zone_sql(), [self.timezone_name])

            finally:

                cursor.close()

        timezone_changed = self.ensure_timezone()

        if timezone_changed:

            # Commit after setting the time zone (see #17062)

            if not self.get_autocommit():

                self.connection.commit()

django/test/signals.py

+1 −4
Original line number Diff line number Diff line
@@ -69,10 +69,7 @@ def update_connections_time_zone(**kwargs): 
                del conn.timezone_name

            except AttributeError:

                pass

            tz_sql = conn.ops.set_time_zone_sql()

            if tz_sql and conn.timezone_name:

                with conn.cursor() as cursor:

                    cursor.execute(tz_sql, [conn.timezone_name])

            conn.ensure_timezone()





@receiver(setting_changed)