code: func (tc *TransactionContext) UpdateDeltaForTable(tableID int64, delta int64, count int64, colSize map[int64]int64) {
  	if tc.TableDeltaMap == nil {
  		tc.TableDeltaMap = make(map[int64]TableDelta)
  	}
  	item := tc.TableDeltaMap[tableID]
  	if item.ColSize == nil && colSize != nil {
  		item.ColSize = make(map[int64]int64)
  	}
  	item.Delta += delta
  	item.Count += count
  	for key, val := range colSize {
  		item.ColSize[key] += val
  	}
  	tc.TableDeltaMap[tableID] = item
  }
docs: // UpdateDeltaForTable updates the delta info for some table.