code: def replace_postgres_db(self, file_url):
          
          self.print_message("Replacing postgres database")
  
          if file_url:
              self.print_message("Sourcing data from online backup file '%s'" % file_url)
              source_file = self.download_file_from_url(self.args.source_app, file_url)
          elif self.databases['source']['name']:
              self.print_message("Sourcing data from database '%s'"
                                 % self.databases['source']['name'])
              source_file = self.dump_database()
          else:
              self.print_message("Sourcing data from local backup file %s" % self.args.file)
              source_file = self.args.file
  
          self.drop_database()
          self.create_database()
  
          source_file = self.unzip_file_if_necessary(source_file)
  
          self.print_message("Importing '%s' into database '%s'"
                             % (source_file, self.databases['destination']['name']))
          args = [
              "pg_restore",
              "--no-acl",
              "--no-owner",
              "--dbname=%s" % self.databases['destination']['name'],
              source_file,
          ]
          args.extend(self.databases['destination']['args'])
          subprocess.check_call(args)
docs: Replace postgres database with database from specified source.