func (a *decimalVarianceAggregate) result() (parser.Datum, error) { if a.count.Cmp(decimalTwo) < 0 { return parser.DNull, nil } a.tmp.Sub(&a.count, decimalOne) dd := parser.DDecimal{} dd.QuoRound(&a.sqrDiff, &a.tmp, decimal.Precision, inf.RoundHalfUp) return dd, nil }