code: func (s *schemaVersionSyncer) OwnerUpdateGlobalVersion(ctx context.Context, version int64) error {
  	startTime := time.Now()
  	ver := strconv.FormatInt(version, 10)
  	// TODO: If the version is larger than the original global version, we need set the version.
  	// Otherwise, we'd better set the original global version.
  	err := PutKVToEtcd(ctx, s.etcdCli, putKeyRetryUnlimited, DDLGlobalSchemaVersion, ver)
  	metrics.OwnerHandleSyncerHistogram.WithLabelValues(metrics.OwnerUpdateGlobalVersion, metrics.RetLabel(err)).Observe(time.Since(startTime).Seconds())
  	return errors.Trace(err)
  }
docs: // OwnerUpdateGlobalVersion implements SchemaSyncer.OwnerUpdateGlobalVersion interface.