code: func (h *Handle) UpdateTableStats(tables []*statistics.Table, deletedIDs []int64) {
  	newCache := h.copyFromOldCache()
  	for _, tbl := range tables {
  		id := tbl.PhysicalID
  		newCache[id] = tbl
  	}
  	for _, id := range deletedIDs {
  		delete(newCache, id)
  	}
  	h.StatsCache.Store(newCache)
  }
docs: // UpdateTableStats updates the statistics table cache using copy on write.