Merge branch 'master' of https://github.com/pingcap/tidb into trace-w…

…rite-memory

types/datum.go

@@ -2060,7 +2060,11 @@ func ChangeReverseResultByUpperLowerBound(
 	return d, nil
 }
 
-const sizeOfEmptyDatum = int(unsafe.Sizeof(Datum{}))
+const (
+	sizeOfEmptyDatum = int(unsafe.Sizeof(Datum{}))
+	sizeOfMysqlTime  = int(unsafe.Sizeof(Time{}))
+	sizeOfMyDecimal  = MyDecimalStructSize
+)
 
 // EstimatedMemUsage returns the estimated bytes consumed of a one-dimensional
 // or two-dimensional datum array.
@@ -2071,12 +2075,12 @@ func EstimatedMemUsage(array []Datum, numOfRows int) int64 {
 	var bytesConsumed int
 	for _, d := range array {
 		switch d.Kind() {
-		case KindString, KindBytes, KindBinaryLiteral, KindMysqlJSON, KindMysqlEnum, KindMysqlSet, KindMysqlBit:
-			bytesConsumed += len(d.b)
 		case KindMysqlDecimal:
-			bytesConsumed += int(unsafe.Sizeof(d.GetMysqlDecimal()))
+			bytesConsumed += sizeOfMyDecimal
 		case KindMysqlTime:
-			bytesConsumed += int(unsafe.Sizeof(d.GetMysqlTime()))
+			bytesConsumed += sizeOfMysqlTime
+		default:
+			bytesConsumed += len(d.b)
 		}
 	}
 	bytesConsumed += len(array) * sizeOfEmptyDatum