admin: fix admin check table bug of byte compare (pingcap#7887)

* admin: remove reflect deepEqual

executor/executor_test.go

@@ -301,6 +301,15 @@ func (s *testSuite) TestAdmin(c *C) {
 	tk.MustExec("alter table t1 add index idx_i(i);")
 	tk.MustExec("alter table t1 add index idx_m(a,c,d,e,f,g,h,i,j);")
 	tk.MustExec("admin check table t1;")
+
+	tk.MustExec("drop table if exists t1;")
+	tk.MustExec("CREATE TABLE t1 (c1 int);")
+	tk.MustExec("INSERT INTO t1 SET c1 = 1;")
+	tk.MustExec("ALTER TABLE t1 ADD COLUMN cc1 CHAR(36)    NULL DEFAULT '';")
+	tk.MustExec("ALTER TABLE t1 ADD COLUMN cc2 VARCHAR(36) NULL DEFAULT ''")
+	tk.MustExec("ALTER TABLE t1 ADD INDEX idx1 (cc1);")
+	tk.MustExec("ALTER TABLE t1 ADD INDEX idx2 (cc2);")
+	tk.MustExec("admin check table t1;")
 }
 
 func (s *testSuite) fillData(tk *testkit.TestKit, table string) {

types/datum_test.go

@@ -14,6 +14,8 @@
 package types
 
 import (
+	"reflect"
+	"testing"
 	"time"
 
 	. "github.com/pingcap/check"
@@ -362,3 +364,39 @@ func (ts *testDatumSuite) TestCopyDatum(c *C) {
 		}
 	}
 }
+
+func prepareCompareDatums() ([]Datum, []Datum) {
+	vals := make([]Datum, 0, 5)
+	vals = append(vals, NewIntDatum(1))
+	vals = append(vals, NewFloat64Datum(1.23))
+	vals = append(vals, NewStringDatum("abcde"))
+	vals = append(vals, NewDecimalDatum(NewDecFromStringForTest("1.2345")))
+	vals = append(vals, NewTimeDatum(Time{Time: FromGoTime(time.Date(2018, 3, 8, 16, 1, 0, 315313000, time.UTC)), Fsp: 6, Type: mysql.TypeTimestamp}))
+
+	vals1 := make([]Datum, 0, 5)
+	vals1 = append(vals1, NewIntDatum(1))
+	vals1 = append(vals1, NewFloat64Datum(1.23))
+	vals1 = append(vals1, NewStringDatum("abcde"))
+	vals1 = append(vals1, NewDecimalDatum(NewDecFromStringForTest("1.2345")))
+	vals1 = append(vals1, NewTimeDatum(Time{Time: FromGoTime(time.Date(2018, 3, 8, 16, 1, 0, 315313000, time.UTC)), Fsp: 6, Type: mysql.TypeTimestamp}))
+	return vals, vals1
+}
+
+func BenchmarkCompareDatum(b *testing.B) {
+	vals, vals1 := prepareCompareDatums()
+	sc := new(stmtctx.StatementContext)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		for j, v := range vals {
+			v.CompareDatum(sc, &vals1[j])
+		}
+	}
+}
+
+func BenchmarkCompareDatumByReflect(b *testing.B) {
+	vals, vals1 := prepareCompareDatums()
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		reflect.DeepEqual(vals, vals1)
+	}
+}

util/admin/admin.go

@@ -16,7 +16,6 @@ package admin
 import (
 	"fmt"
 	"io"
-	"reflect"
 	"sort"
 
 	"github.com/pingcap/tidb/expression"
@@ -353,7 +352,7 @@ func checkIndexAndRecord(sessCtx sessionctx.Context, txn kv.Transaction, t table
 	if err != nil {
 		return errors.Trace(err)
 	}
-	sc := new(stmtctx.StatementContext)
+	sc := sessCtx.GetSessionVars().StmtCtx
 	for {
 		vals1, h, err := it.Next()
 		if terror.ErrorEqual(err, io.EOF) {
@@ -391,15 +390,9 @@ func compareDatumSlice(sc *stmtctx.StatementContext, val1s, val2s []types.Datum)
 		return false
 	}
 	for i, v := range val1s {
-		if v.Kind() == types.KindMysqlDecimal {
-			res, err := v.CompareDatum(sc, &val2s[i])
-			if err != nil || res != 0 {
-				return false
-			}
-		} else {
-			if !reflect.DeepEqual(v, val2s[i]) {
-				return false
-			}
+		res, err := v.CompareDatum(sc, &val2s[i])
+		if err != nil || res != 0 {
+			return false
 		}
 	}
 	return true
@@ -523,6 +516,7 @@ func CompareTableRecord(sessCtx sessionctx.Context, txn kv.Transaction, t table.
 	}
 
 	startKey := t.RecordKey(0)
+	sc := sessCtx.GetSessionVars().StmtCtx
 	filterFunc := func(h int64, vals []types.Datum, cols []*table.Column) (bool, error) {
 		vals2, ok := m[h]
 		if !ok {
@@ -534,7 +528,7 @@ func CompareTableRecord(sessCtx sessionctx.Context, txn kv.Transaction, t table.
 			return true, nil
 		}
 
-		if !reflect.DeepEqual(vals, vals2) {
+		if !compareDatumSlice(sc, vals, vals2) {
 			record1 := &RecordData{Handle: h, Values: vals2}
 			record2 := &RecordData{Handle: h, Values: vals}
 			return false, ErrDataInConsistent.GenWithStack("data:%#v != record:%#v", record1, record2)