executor: set column data to zero value when calling ResizeXXX (#13260

)

util/chunk/column.go

@@ -243,6 +243,10 @@ const (
 	sizeTime       = int(unsafe.Sizeof(types.Time{}))
 )
 
+var (
+	emptyBuf = make([]byte, 4*1024)
+)
+
 // resize resizes the column so that it contains n elements, only valid for fixed-length types.
 func (c *Column) resize(n, typeSize int, isNull bool) {
 	sizeData := n * typeSize
@@ -251,6 +255,11 @@ func (c *Column) resize(n, typeSize int, isNull bool) {
 	} else {
 		c.data = make([]byte, sizeData)
 	}
+	if !isNull {
+		for j := 0; j < sizeData; j += len(emptyBuf) {
+			copy(c.data[j:], emptyBuf)
+		}
+	}
 
 	newNulls := false
 	sizeNulls := (n + 7) >> 3

util/chunk/column_test.go

@@ -780,6 +780,66 @@ func (s *testChunkSuite) TestGetRaw(c *check.C) {
 	}
 }
 
+func (s *testChunkSuite) TestResize(c *check.C) {
+	col := NewColumn(types.NewFieldType(mysql.TypeLonglong), 1024)
+	for i := 0; i < 1024; i++ {
+		col.AppendInt64(int64(i))
+	}
+	col.ResizeInt64(1024, false)
+	for i := 0; i < 1024; i++ {
+		c.Assert(col.Int64s()[i], check.Equals, int64(0))
+	}
+
+	col = NewColumn(types.NewFieldType(mysql.TypeFloat), 1024)
+	for i := 0; i < 1024; i++ {
+		col.AppendFloat32(float32(i))
+	}
+	col.ResizeFloat32(1024, false)
+	for i := 0; i < 1024; i++ {
+		c.Assert(col.Float32s()[i], check.Equals, float32(0))
+	}
+
+	col = NewColumn(types.NewFieldType(mysql.TypeDouble), 1024)
+	for i := 0; i < 1024; i++ {
+		col.AppendFloat64(float64(i))
+	}
+	col.ResizeFloat64(1024, false)
+	for i := 0; i < 1024; i++ {
+		c.Assert(col.Float64s()[i], check.Equals, float64(0))
+	}
+
+	col = NewColumn(types.NewFieldType(mysql.TypeNewDecimal), 1024)
+	for i := 0; i < 1024; i++ {
+		col.AppendMyDecimal(new(types.MyDecimal).FromInt(int64(i)))
+	}
+	col.ResizeDecimal(1024, false)
+	for i := 0; i < 1024; i++ {
+		var d types.MyDecimal
+		c.Assert(col.Decimals()[i], check.Equals, d)
+	}
+
+	col = NewColumn(types.NewFieldType(mysql.TypeDuration), 1024)
+	for i := 0; i < 1024; i++ {
+		col.AppendDuration(types.Duration{Duration: time.Duration(i), Fsp: int8(i)})
+	}
+	col.ResizeGoDuration(1024, false)
+	for i := 0; i < 1024; i++ {
+		c.Assert(col.GoDurations()[i], check.Equals, time.Duration(0))
+	}
+
+	col = NewColumn(types.NewFieldType(mysql.TypeDatetime), 1024)
+	for i := 0; i < 1024; i++ {
+		gt := types.FromDate(rand.Intn(2200), rand.Intn(10)+1, rand.Intn(20)+1, rand.Intn(12), rand.Intn(60), rand.Intn(60), rand.Intn(1000000))
+		t := types.Time{Time: gt}
+		col.AppendTime(t)
+	}
+	col.ResizeTime(1024, false)
+	for i := 0; i < 1024; i++ {
+		var t types.Time
+		c.Assert(col.Times()[i], check.Equals, t)
+	}
+}
+
 func BenchmarkDurationRow(b *testing.B) {
 	chk1 := NewChunkWithCapacity([]*types.FieldType{types.NewFieldType(mysql.TypeDuration)}, 1024)
 	col1 := chk1.Column(0)