Merge branch 'release-5.2' of github.com:pingcap/tidb into release-5.…

…2-8cf847a57514

executor/aggfuncs/aggfuncs.go

@@ -187,9 +187,8 @@ type baseAggFunc struct {
 	// used to append the final result of this function.
 	ordinal int
 
-	// frac stores digits of the fractional part of decimals,
-	// which makes the decimal be the result of type inferring.
-	frac int
+	// retTp means the target type of the final agg should return.
+	retTp *types.FieldType
 }
 
 func (*baseAggFunc) MergePartialResult(sctx sessionctx.Context, src, dst PartialResult) (memDelta int64, err error) {

executor/aggfuncs/builder.go

@@ -17,7 +17,6 @@ import (
 	"fmt"
 	"strconv"
 
-	"github.com/cznic/mathutil"
 	"github.com/pingcap/parser/ast"
 	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/expression"
@@ -194,6 +193,7 @@ func buildCount(aggFuncDesc *aggregation.AggFuncDesc, ordinal int) AggFunc {
 	base := baseAggFunc{
 		args:    aggFuncDesc.Args,
 		ordinal: ordinal,
+		retTp:   aggFuncDesc.RetTp,
 	}
 
 	// If HasDistinct and mode is CompleteMode or Partial1Mode, we should
@@ -253,13 +253,9 @@ func buildSum(ctx sessionctx.Context, aggFuncDesc *aggregation.AggFuncDesc, ordi
 		baseAggFunc: baseAggFunc{
 			args:    aggFuncDesc.Args,
 			ordinal: ordinal,
+			retTp:   aggFuncDesc.RetTp,
 		},
 	}
-	frac := base.args[0].GetType().Decimal
-	if frac == -1 {
-		frac = mysql.MaxDecimalScale
-	}
-	base.frac = mathutil.Min(frac, mysql.MaxDecimalScale)
 	switch aggFuncDesc.Mode {
 	case aggregation.DedupMode:
 		return nil
@@ -287,16 +283,8 @@ func buildAvg(ctx sessionctx.Context, aggFuncDesc *aggregation.AggFuncDesc, ordi
 	base := baseAggFunc{
 		args:    aggFuncDesc.Args,
 		ordinal: ordinal,
+		retTp:   aggFuncDesc.RetTp,
 	}
-	frac := base.args[0].GetType().Decimal
-	if len(base.args) == 2 {
-		frac = base.args[1].GetType().Decimal
-	}
-	if frac == -1 {
-		frac = mysql.MaxDecimalScale
-	}
-	base.frac = mathutil.Min(frac, mysql.MaxDecimalScale)
-
 	switch aggFuncDesc.Mode {
 	// Build avg functions which consume the original data and remove the
 	// duplicated input of the same group.
@@ -340,13 +328,8 @@ func buildFirstRow(aggFuncDesc *aggregation.AggFuncDesc, ordinal int) AggFunc {
 	base := baseAggFunc{
 		args:    aggFuncDesc.Args,
 		ordinal: ordinal,
+		retTp:   aggFuncDesc.RetTp,
 	}
-	frac := base.args[0].GetType().Decimal
-	if frac == -1 {
-		frac = mysql.MaxDecimalScale
-	}
-	base.frac = mathutil.Min(frac, mysql.MaxDecimalScale)
-
 	evalType, fieldType := aggFuncDesc.RetTp.EvalType(), aggFuncDesc.RetTp
 	if fieldType.Tp == mysql.TypeBit {
 		evalType = types.ETString
@@ -392,16 +375,11 @@ func buildMaxMin(aggFuncDesc *aggregation.AggFuncDesc, ordinal int, isMax bool)
 		baseAggFunc: baseAggFunc{
 			args:    aggFuncDesc.Args,
 			ordinal: ordinal,
+			retTp:   aggFuncDesc.RetTp,
 		},
 		isMax:    isMax,
 		collator: collate.GetCollator(aggFuncDesc.RetTp.Collate),
 	}
-	frac := base.args[0].GetType().Decimal
-	if frac == -1 {
-		frac = mysql.MaxDecimalScale
-	}
-	base.frac = mathutil.Min(frac, mysql.MaxDecimalScale)
-
 	evalType, fieldType := aggFuncDesc.RetTp.EvalType(), aggFuncDesc.RetTp
 	if fieldType.Tp == mysql.TypeBit {
 		evalType = types.ETString

executor/aggfuncs/func_avg.go

@@ -16,6 +16,8 @@ package aggfuncs
 import (
 	"unsafe"
 
+	"github.com/pingcap/errors"
+	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
@@ -71,7 +73,14 @@ func (e *baseAvgDecimal) AppendFinalResult2Chunk(sctx sessionctx.Context, pr Par
 	if err != nil {
 		return err
 	}
-	err = finalResult.Round(finalResult, e.frac, types.ModeHalfEven)
+	if e.retTp == nil {
+		return errors.New("e.retTp of avg should not be nil")
+	}
+	frac := e.retTp.Decimal
+	if frac == -1 {
+		frac = mysql.MaxDecimalScale
+	}
+	err = finalResult.Round(finalResult, frac, types.ModeHalfEven)
 	if err != nil {
 		return err
 	}
@@ -259,7 +268,14 @@ func (e *avgOriginal4DistinctDecimal) AppendFinalResult2Chunk(sctx sessionctx.Co
 	if err != nil {
 		return err
 	}
-	err = finalResult.Round(finalResult, e.frac, types.ModeHalfEven)
+	if e.retTp == nil {
+		return errors.New("e.retTp of avg should not be nil")
+	}
+	frac := e.retTp.Decimal
+	if frac == -1 {
+		frac = mysql.MaxDecimalScale
+	}
+	err = finalResult.Round(finalResult, frac, types.ModeHalfEven)
 	if err != nil {
 		return err
 	}

executor/aggfuncs/func_first_row.go

@@ -16,6 +16,8 @@ package aggfuncs
 import (
 	"unsafe"
 
+	"github.com/pingcap/errors"
+	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/types/json"
@@ -475,7 +477,14 @@ func (e *firstRow4Decimal) AppendFinalResult2Chunk(sctx sessionctx.Context, pr P
 		chk.AppendNull(e.ordinal)
 		return nil
 	}
-	err := p.val.Round(&p.val, e.frac, types.ModeHalfEven)
+	if e.retTp == nil {
+		return errors.New("e.retTp of first_row should not be nil")
+	}
+	frac := e.retTp.Decimal
+	if frac == -1 {
+		frac = mysql.MaxDecimalScale
+	}
+	err := p.val.Round(&p.val, frac, types.ModeHalfEven)
 	if err != nil {
 		return err
 	}

executor/aggfuncs/func_max_min.go

@@ -17,6 +17,7 @@ import (
 	"unsafe"
 
 	"github.com/pingcap/errors"
+	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/types/json"
@@ -813,7 +814,14 @@ func (e *maxMin4Decimal) AppendFinalResult2Chunk(sctx sessionctx.Context, pr Par
 		chk.AppendNull(e.ordinal)
 		return nil
 	}
-	err := p.val.Round(&p.val, e.frac, types.ModeHalfEven)
+	if e.retTp == nil {
+		return errors.New("e.retTp of max or min should not be nil")
+	}
+	frac := e.retTp.Decimal
+	if frac == -1 {
+		frac = mysql.MaxDecimalScale
+	}
+	err := p.val.Round(&p.val, frac, types.ModeHalfEven)
 	if err != nil {
 		return err
 	}

executor/aggfuncs/func_sum.go

@@ -16,6 +16,8 @@ package aggfuncs
 import (
 	"unsafe"
 
+	"github.com/pingcap/errors"
+	"github.com/pingcap/parser/mysql"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/types"
 	"github.com/pingcap/tidb/util/chunk"
@@ -168,7 +170,14 @@ func (e *sum4Decimal) AppendFinalResult2Chunk(sctx sessionctx.Context, pr Partia
 		chk.AppendNull(e.ordinal)
 		return nil
 	}
-	err := p.val.Round(&p.val, e.frac, types.ModeHalfEven)
+	if e.retTp == nil {
+		return errors.New("e.retTp of sum should not be nil")
+	}
+	frac := e.retTp.Decimal
+	if frac == -1 {
+		frac = mysql.MaxDecimalScale
+	}
+	err := p.val.Round(&p.val, frac, types.ModeHalfEven)
 	if err != nil {
 		return err
 	}

executor/executor_test.go

@@ -9247,6 +9247,44 @@ func (s *testSerialSuite) TestUnreasonablyClose(c *C) {
 	c.Assert(opsAlreadyCoveredMask, Equals, opsNeedsCoveredMask, Commentf("these operators are not covered %s", commentBuf.String()))
 }
 
+func (s *testSerialSuite) TestIssue29498(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("DROP TABLE IF EXISTS t1;")
+	tk.MustExec("CREATE TABLE t1 (t3 TIME(3), d DATE, t TIME);")
+	tk.MustExec("INSERT INTO t1 VALUES ('00:00:00.567', '2002-01-01', '00:00:02');")
+
+	res := tk.MustQuery("SELECT CONCAT(IFNULL(t3, d)) AS col1 FROM t1;")
+	row := res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp+3+1)
+	c.Assert(row[len(row)-12:], Equals, "00:00:00.567")
+
+	res = tk.MustQuery("SELECT IFNULL(t3, d) AS col1 FROM t1;")
+	row = res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp+3+1)
+	c.Assert(row[len(row)-12:], Equals, "00:00:00.567")
+
+	res = tk.MustQuery("SELECT CONCAT(IFNULL(t, d)) AS col1 FROM t1;")
+	row = res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp)
+	c.Assert(row[len(row)-8:], Equals, "00:00:02")
+
+	res = tk.MustQuery("SELECT IFNULL(t, d) AS col1 FROM t1;")
+	row = res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp)
+	c.Assert(row[len(row)-8:], Equals, "00:00:02")
+
+	res = tk.MustQuery("SELECT CONCAT(xx) FROM (SELECT t3 AS xx FROM t1 UNION SELECT d FROM t1) x ORDER BY -xx LIMIT 1;")
+	row = res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp+3+1)
+	c.Assert(row[len(row)-12:], Equals, "00:00:00.567")
+
+	res = tk.MustQuery("SELECT CONCAT(CASE WHEN d IS NOT NULL THEN t3 ELSE d END) AS col1 FROM t1;")
+	row = res.Rows()[0][0].(string)
+	c.Assert(len(row), Equals, mysql.MaxDatetimeWidthNoFsp+3+1)
+	c.Assert(row[len(row)-12:], Equals, "00:00:00.567")
+}
+
 func (s *testSuite) TestDeleteWithMulTbl(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 

executor/tiflash_test.go

@@ -740,11 +740,28 @@ func (s *tiflashTestSuite) TestUnionWithEmptyDualTable(c *C) {
 func (s *tiflashTestSuite) TestAvgOverflow(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")
+	// avg int
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t (a decimal(1,0))")
+	tk.MustExec("alter table t set tiflash replica 1")
+	tb := testGetTableByName(c, tk.Se, "test", "t")
+	err := domain.GetDomain(tk.Se).DDL().UpdateTableReplicaInfo(tk.Se, tb.Meta().ID, true)
+	c.Assert(err, IsNil)
+	tk.MustExec("insert into t values(9)")
+	for i := 0; i < 16; i++ {
+		tk.MustExec("insert into t select * from t")
+	}
+	tk.MustExec("set @@session.tidb_isolation_read_engines=\"tiflash\"")
+	tk.MustExec("set @@session.tidb_enforce_mpp=ON")
+	tk.MustQuery("select avg(a) from t group by a").Check(testkit.Rows("9.0000"))
+	tk.MustExec("drop table if exists t")
+
+	// avg decimal
 	tk.MustExec("drop table if exists td;")
 	tk.MustExec("create table td (col_bigint bigint(20), col_smallint smallint(6));")
 	tk.MustExec("alter table td set tiflash replica 1")
-	tb := testGetTableByName(c, tk.Se, "test", "td")
-	err := domain.GetDomain(tk.Se).DDL().UpdateTableReplicaInfo(tk.Se, tb.Meta().ID, true)
+	tb = testGetTableByName(c, tk.Se, "test", "td")
+	err = domain.GetDomain(tk.Se).DDL().UpdateTableReplicaInfo(tk.Se, tb.Meta().ID, true)
 	c.Assert(err, IsNil)
 	tk.MustExec("insert into td values (null, 22876);")
 	tk.MustExec("insert into td values (9220557287087669248, 32767);")

expression/aggregation/base_func.go

@@ -42,7 +42,7 @@ type baseFuncDesc struct {
 
 func newBaseFuncDesc(ctx sessionctx.Context, name string, args []expression.Expression) (baseFuncDesc, error) {
 	b := baseFuncDesc{Name: strings.ToLower(name), Args: args}
-	err := b.typeInfer(ctx)
+	err := b.TypeInfer(ctx)
 	return b, err
 }
 
@@ -83,8 +83,8 @@ func (a *baseFuncDesc) String() string {
 	return buffer.String()
 }
 
-// typeInfer infers the arguments and return types of an function.
-func (a *baseFuncDesc) typeInfer(ctx sessionctx.Context) error {
+// TypeInfer infers the arguments and return types of an function.
+func (a *baseFuncDesc) TypeInfer(ctx sessionctx.Context) error {
 	switch a.Name {
 	case ast.AggFuncCount:
 		a.typeInfer4Count(ctx)
@@ -206,6 +206,14 @@ func (a *baseFuncDesc) typeInfer4Sum(ctx sessionctx.Context) {
 	types.SetBinChsClnFlag(a.RetTp)
 }
 
+// TypeInfer4AvgSum infers the type of sum from avg, which should extend the precision of decimal
+// compatible with mysql.
+func (a *baseFuncDesc) TypeInfer4AvgSum(avgRetType *types.FieldType) {
+	if avgRetType.Tp == mysql.TypeNewDecimal {
+		a.RetTp.Flen = mathutil.Min(mysql.MaxDecimalWidth, a.RetTp.Flen+22)
+	}
+}
+
 // typeInfer4Avg should returns a "decimal", otherwise it returns a "double".
 // Because child returns integer or decimal type.
 func (a *baseFuncDesc) typeInfer4Avg(ctx sessionctx.Context) {
@@ -245,6 +253,12 @@ func (a *baseFuncDesc) typeInfer4GroupConcat(ctx sessionctx.Context) {
 
 	a.RetTp.Flen, a.RetTp.Decimal = mysql.MaxBlobWidth, 0
 	// TODO: a.Args[i] = expression.WrapWithCastAsString(ctx, a.Args[i])
+	for i := 0; i < len(a.Args)-1; i++ {
+		if tp := a.Args[i].GetType(); tp.Tp == mysql.TypeNewDecimal {
+			a.Args[i] = expression.BuildCastFunction(ctx, a.Args[i], tp)
+		}
+	}
+
 }
 
 func (a *baseFuncDesc) typeInfer4MaxMin(ctx sessionctx.Context) {
@@ -368,18 +382,6 @@ var noNeedCastAggFuncs = map[string]struct{}{
 	ast.AggFuncJsonObjectAgg:       {},
 }
 
-// WrapCastAsDecimalForAggArgs wraps the args of some specific aggregate functions
-// with a cast as decimal function. See issue #19426
-func (a *baseFuncDesc) WrapCastAsDecimalForAggArgs(ctx sessionctx.Context) {
-	if a.Name == ast.AggFuncGroupConcat {
-		for i := 0; i < len(a.Args)-1; i++ {
-			if tp := a.Args[i].GetType(); tp.Tp == mysql.TypeNewDecimal {
-				a.Args[i] = expression.BuildCastFunction(ctx, a.Args[i], tp)
-			}
-		}
-	}
-}
-
 // WrapCastForAggArgs wraps the args of an aggregate function with a cast function.
 func (a *baseFuncDesc) WrapCastForAggArgs(ctx sessionctx.Context) {
 	if len(a.Args) == 0 {

expression/builtin_cast.go

@@ -290,6 +290,9 @@ func (c *castAsStringFunctionClass) getFunction(ctx sessionctx.Context, args []E
 	argTp := args[0].GetType().EvalType()
 	switch argTp {
 	case types.ETInt:
+		if bf.tp.Flen == types.UnspecifiedLength {
+			bf.tp.Flen = args[0].GetType().Flen
+		}
 		sig = &builtinCastIntAsStringSig{bf}
 		sig.setPbCode(tipb.ScalarFuncSig_CastIntAsString)
 	case types.ETReal: