code: func (h *Handle) DumpStatsDeltaToKV(dumpMode bool) error {
  	h.sweepList()
  	currentTime := time.Now()
  	for id, item := range h.globalMap {
  		if dumpMode == DumpDelta && !needDumpStatsDelta(h, id, item, currentTime) {
  			continue
  		}
  		updated, err := h.dumpTableStatCountToKV(id, item)
  		if err != nil {
  			return errors.Trace(err)
  		}
  		if updated {
  			h.globalMap.update(id, -item.Delta, -item.Count, nil)
  		}
  		if err = h.dumpTableStatColSizeToKV(id, item); err != nil {
  			return errors.Trace(err)
  		}
  		if updated {
  			delete(h.globalMap, id)
  		} else {
  			m := h.globalMap[id]
  			m.ColSize = nil
  			h.globalMap[id] = m
  		}
  	}
  	return nil
  }
docs: // DumpStatsDeltaToKV sweeps the whole list and updates the global map, then we dumps every table that held in map to KV.
  // If the `dumpAll` is false, it will only dump that delta info that `Modify Count / Table Count` greater than a ratio.