class method self.load_schema_if_pending!

# File activerecord/lib/active_record/migration.rb, line 708
      def load_schema_if_pending!
        any_schema_needs_update = false
        pending_migrations = []

        db_configs_in_current_env.each do |db_config|
          ActiveRecord::PendingMigrationConnection.with_temporary_pool(db_config) do |pool|
            any_schema_needs_update ||= schema_needs_update?(db_config, pool)

            pending = pool.migration_context.open.pending_migrations
            pending_migrations.concat(pending)
          end
        end

        if any_schema_needs_update
          load_schema!

          pending_migrations = []
          db_configs_in_current_env.each do |db_config|
            ActiveRecord::PendingMigrationConnection.with_temporary_pool(db_config) do |pool|
              pending = pool.migration_context.open.pending_migrations
              pending_migrations.concat(pending)
            end
          end
        end

        check_pending_migrations(pending_migrations)
      end