Merge remote-tracking branch 'upstream/master' into support_change_ch…

…arset_utf8

CONTRIBUTING.md

@@ -61,7 +61,7 @@ TiDB is written in [Go](http://golang.org).
 If you don't have a Go development environment,
 please [set one up](http://golang.org/doc/code.html).
 
-The version of GO should be **1.10** or above.
+The version of GO should be **1.11** or above.
 
 After installation, you'll need `GOPATH` defined,
 and `PATH` modified to access your Go binaries.
@@ -75,11 +75,7 @@ export PATH=$PATH:$GOPATH/bin
 
 #### Dependency management
 
-TiDB uses [`dep`](https://github.com/golang/dep) to manage dependencies.
-
-```sh
-go get -u github.com/golang/dep/cmd/dep
-```
+TiDB uses [`Go Modules`](https://github.com/golang/go/wiki/Modules) to manage dependencies.
 
 ## Workflow
 

Makefile

@@ -101,6 +101,7 @@ vet:
 clean:
 	$(GO) clean -i ./...
 	rm -rf *.out
+	rm -rf parser
 
 test: checklist gotest explaintest
 
@@ -144,13 +145,13 @@ tikv_integration_test:
 	$(GOTEST) ./store/tikv/. -with-tikv=true || { $(GOFAIL_DISABLE); exit 1; }
 	@$(GOFAIL_DISABLE)
 
-RACE_FLAG = 
+RACE_FLAG =
 ifeq ("$(WITH_RACE)", "1")
 	RACE_FLAG = -race
 	GOBUILD   = GOPATH=$(GOPATH) CGO_ENABLED=1 $(GO) build
 endif
 
-CHECK_FLAG = 
+CHECK_FLAG =
 ifeq ("$(WITH_CHECK)", "1")
 	CHECK_FLAG = $(TEST_LDFLAGS)
 endif

cmd/explaintest/r/explain_easy.result

@@ -159,18 +159,18 @@ TableReader_5	10000.00	root	data:TableScan_4
 explain select c1 from t2 union select c1 from t2 union all select c1 from t2;
 id	count	task	operator info
 Union_17	26000.00	root	
-├─TableReader_20	10000.00	root	data:TableScan_19
-│ └─TableScan_19	10000.00	cop	table:t2, range:[-inf,+inf], keep order:false, stats:pseudo
-└─HashAgg_24	16000.00	root	group by:t2.c1, funcs:firstrow(join_agg_0)
-  └─Union_25	16000.00	root	
-    ├─StreamAgg_38	8000.00	root	group by:col_2, funcs:firstrow(col_0), firstrow(col_1)
-    │ └─IndexReader_39	8000.00	root	index:StreamAgg_29
-    │   └─StreamAgg_29	8000.00	cop	group by:test.t2.c1, funcs:firstrow(test.t2.c1), firstrow(test.t2.c1)
-    │     └─IndexScan_37	10000.00	cop	table:t2, index:c1, range:[NULL,+inf], keep order:true, stats:pseudo
-    └─StreamAgg_55	8000.00	root	group by:col_2, funcs:firstrow(col_0), firstrow(col_1)
-      └─IndexReader_56	8000.00	root	index:StreamAgg_46
-        └─StreamAgg_46	8000.00	cop	group by:test.t2.c1, funcs:firstrow(test.t2.c1), firstrow(test.t2.c1)
-          └─IndexScan_54	10000.00	cop	table:t2, index:c1, range:[NULL,+inf], keep order:true, stats:pseudo
+├─HashAgg_21	16000.00	root	group by:t2.c1, funcs:firstrow(join_agg_0)
+│ └─Union_22	16000.00	root	
+│   ├─StreamAgg_35	8000.00	root	group by:col_2, funcs:firstrow(col_0), firstrow(col_1)
+│   │ └─IndexReader_36	8000.00	root	index:StreamAgg_26
+│   │   └─StreamAgg_26	8000.00	cop	group by:test.t2.c1, funcs:firstrow(test.t2.c1), firstrow(test.t2.c1)
+│   │     └─IndexScan_34	10000.00	cop	table:t2, index:c1, range:[NULL,+inf], keep order:true, stats:pseudo
+│   └─StreamAgg_52	8000.00	root	group by:col_2, funcs:firstrow(col_0), firstrow(col_1)
+│     └─IndexReader_53	8000.00	root	index:StreamAgg_43
+│       └─StreamAgg_43	8000.00	cop	group by:test.t2.c1, funcs:firstrow(test.t2.c1), firstrow(test.t2.c1)
+│         └─IndexScan_51	10000.00	cop	table:t2, index:c1, range:[NULL,+inf], keep order:true, stats:pseudo
+└─TableReader_59	10000.00	root	data:TableScan_58
+  └─TableScan_58	10000.00	cop	table:t2, range:[-inf,+inf], keep order:false, stats:pseudo
 explain select c1 from t2 union all select c1 from t2 union select c1 from t2;
 id	count	task	operator info
 HashAgg_18	24000.00	root	group by:t2.c1, funcs:firstrow(join_agg_0)
@@ -393,6 +393,19 @@ Projection_5	8000.00	root	test.ta.a
     └─TableReader_9	10000.00	root	data:TableScan_8
       └─TableScan_8	10000.00	cop	table:ta, range:[-inf,+inf], keep order:false, stats:pseudo
 rollback;
+drop table if exists t1, t2;
+create table t1(a int, b int, c int, primary key(a, b));
+create table t2(a int, b int, c int, primary key(a));
+explain select t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a;
+id	count	task	operator info
+TableReader_7	10000.00	root	data:TableScan_6
+└─TableScan_6	10000.00	cop	table:t1, range:[-inf,+inf], keep order:false, stats:pseudo
+explain select distinct t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a;
+id	count	task	operator info
+StreamAgg_19	8000.00	root	group by:col_2, col_3, funcs:firstrow(col_0), firstrow(col_1)
+└─IndexReader_20	8000.00	root	index:StreamAgg_10
+  └─StreamAgg_10	8000.00	cop	group by:test.t1.a, test.t1.b, funcs:firstrow(test.t1.a), firstrow(test.t1.b)
+    └─IndexScan_18	10000.00	cop	table:t1, index:a, b, range:[NULL,+inf], keep order:true, stats:pseudo
 drop table if exists t;
 create table t(a int, nb int not null, nc int not null);
 explain select ifnull(a, 0) from t;

cmd/explaintest/t/explain_easy.test

@@ -82,6 +82,13 @@ insert tb values ('1');
 explain select * from ta where a = 1;
 rollback;
 
+# outer join elimination
+drop table if exists t1, t2;
+create table t1(a int, b int, c int, primary key(a, b));
+create table t2(a int, b int, c int, primary key(a));
+explain select t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a;
+explain select distinct t1.a, t1.b from t1 left outer join t2 on t1.a = t2.a;
+
 # https://github.com/pingcap/tidb/issues/7918
 drop table if exists t;
 create table t(a int, nb int not null, nc int not null);

config/config.go

@@ -90,7 +90,7 @@ type Log struct {
 	SlowQueryFile      string `toml:"slow-query-file" json:"slow-query-file"`
 	SlowThreshold      uint64 `toml:"slow-threshold" json:"slow-threshold"`
 	ExpensiveThreshold uint   `toml:"expensive-threshold" json:"expensive-threshold"`
-	QueryLogMaxLen     uint   `toml:"query-log-max-len" json:"query-log-max-len"`
+	QueryLogMaxLen     uint64 `toml:"query-log-max-len" json:"query-log-max-len"`
 }
 
 // Security is the security section of the config.
@@ -277,7 +277,7 @@ var defaultConf = Config{
 		},
 		SlowThreshold:      logutil.DefaultSlowThreshold,
 		ExpensiveThreshold: 10000,
-		QueryLogMaxLen:     2048,
+		QueryLogMaxLen:     logutil.DefaultQueryLogMaxLen,
 	},
 	Status: Status{
 		ReportStatus:    true,

ddl/db_change_test.go

@@ -96,9 +96,9 @@ func (s *testStateChangeSuite) TestShowCreateTable(c *C) {
 			got := result.Rows()[0][1]
 			var expected string
 			if job.Type == model.ActionAddIndex {
-				expected = "CREATE TABLE `t` (\n  `id` int(11) DEFAULT NULL,\n  KEY `idx` (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+				expected = "CREATE TABLE `t` (\n  `id` int(11) DEFAULT NULL,\n  KEY `idx` (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 			} else if job.Type == model.ActionAddColumn {
-				expected = "CREATE TABLE `t` (\n  `id` int(11) DEFAULT NULL,\n  KEY `idx` (`id`),\n  KEY `idx1` (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+				expected = "CREATE TABLE `t` (\n  `id` int(11) DEFAULT NULL,\n  KEY `idx` (`id`),\n  KEY `idx1` (`id`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 			}
 			if got != expected {
 				checkErr = errors.Errorf("got %s, expected %s", got, expected)

ddl/db_test.go

@@ -1322,7 +1322,7 @@ func (s *testDBSuite) TestAlterColumn(c *C) {
 	c.Assert(err, NotNil)
 	result := s.tk.MustQuery("show create table mc")
 	createSQL := result.Rows()[0][1]
-	expected := "CREATE TABLE `mc` (\n  `a` int(11) NOT NULL,\n  `b` int(11) DEFAULT NULL,\n  `c` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+	expected := "CREATE TABLE `mc` (\n  `a` int(11) NOT NULL,\n  `b` int(11) DEFAULT NULL,\n  `c` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 	c.Assert(createSQL, Equals, expected)
 
 	// Change / modify column should preserve index options.
@@ -1333,7 +1333,7 @@ func (s *testDBSuite) TestAlterColumn(c *C) {
 	s.mustExec(c, "alter table mc modify column c bigint") // Unique should be preserved
 	result = s.tk.MustQuery("show create table mc")
 	createSQL = result.Rows()[0][1]
-	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL,\n  `b` bigint(20) DEFAULT NULL,\n  `c` bigint(20) DEFAULT NULL,\n  PRIMARY KEY (`a`),\n  UNIQUE KEY `c` (`c`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL,\n  `b` bigint(20) DEFAULT NULL,\n  `c` bigint(20) DEFAULT NULL,\n  PRIMARY KEY (`a`),\n  UNIQUE KEY `c` (`c`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 	c.Assert(createSQL, Equals, expected)
 
 	// Dropping or keeping auto_increment is allowed, however adding is not allowed.
@@ -1342,11 +1342,11 @@ func (s *testDBSuite) TestAlterColumn(c *C) {
 	s.mustExec(c, "alter table mc modify column a bigint auto_increment") // Keeps auto_increment
 	result = s.tk.MustQuery("show create table mc")
 	createSQL = result.Rows()[0][1]
-	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL AUTO_INCREMENT,\n  `b` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL AUTO_INCREMENT,\n  `b` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 	s.mustExec(c, "alter table mc modify column a bigint") // Drops auto_increment
 	result = s.tk.MustQuery("show create table mc")
 	createSQL = result.Rows()[0][1]
-	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL,\n  `b` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"
+	expected = "CREATE TABLE `mc` (\n  `a` bigint(20) NOT NULL,\n  `b` int(11) DEFAULT NULL,\n  PRIMARY KEY (`a`)\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"
 	c.Assert(createSQL, Equals, expected)
 	_, err = s.tk.Exec("alter table mc modify column a bigint auto_increment") // Adds auto_increment should throw error
 	c.Assert(err, NotNil)
@@ -1762,7 +1762,7 @@ func (s *testDBSuite) TestCreateTableWithPartition(c *C) {
 			  partition p0 values less than (to_seconds('2004-01-01')),
 			  partition p1 values less than (to_seconds('2005-01-01')));`)
 	s.tk.MustQuery("show create table t26").Check(
-		testkit.Rows("t26 CREATE TABLE `t26` (\n  `a` date DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin\nPARTITION BY RANGE ( to_seconds(`a`) ) (\n  PARTITION p0 VALUES LESS THAN (63240134400),\n  PARTITION p1 VALUES LESS THAN (63271756800)\n)"))
+		testkit.Rows("t26 CREATE TABLE `t26` (\n  `a` date DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin\nPARTITION BY RANGE ( to_seconds(`a`) ) (\n  PARTITION p0 VALUES LESS THAN (63240134400),\n  PARTITION p1 VALUES LESS THAN (63271756800)\n)"))
 	s.tk.MustExec(`create table t27 (a bigint unsigned not null) 	
 		  partition by range(a) (
 		  partition p0 values less than (10),
@@ -1892,7 +1892,7 @@ func (s *testDBSuite) TestTruncateTable(c *C) {
 	hasOldTableData := true
 	for i := 0; i < waitForCleanDataRound; i++ {
 		err = kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
-			it, err1 := txn.Seek(tablePrefix)
+			it, err1 := txn.Iter(tablePrefix, nil)
 			if err1 != nil {
 				return err1
 			}
@@ -2112,7 +2112,7 @@ func (s *testDBSuite) TestChangeColumnPosition(c *C) {
 		"  `c` int(11) DEFAULT NULL,",
 		"  `a` int(11) DEFAULT NULL,",
 		"  KEY `t` (`c`)",
-		") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin",
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	}
 	c.Assert(createSQL, Equals, strings.Join(exceptedSQL, "\n"))
 }
@@ -2131,7 +2131,7 @@ func (s *testDBSuite) TestGeneratedColumnDDL(c *C) {
 	// Check show create table with virtual generated column.
 	result = s.tk.MustQuery(`show create table test_gv_ddl`)
 	result.Check(testkit.Rows(
-		"test_gv_ddl CREATE TABLE `test_gv_ddl` (\n  `a` int(11) DEFAULT NULL,\n  `b` int(11) GENERATED ALWAYS AS (`a` + 8) VIRTUAL DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin",
+		"test_gv_ddl CREATE TABLE `test_gv_ddl` (\n  `a` int(11) DEFAULT NULL,\n  `b` int(11) GENERATED ALWAYS AS (`a` + 8) VIRTUAL DEFAULT NULL\n) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 
 	// Check alter table add a stored generated column.
@@ -2145,7 +2145,7 @@ func (s *testDBSuite) TestGeneratedColumnDDL(c *C) {
 	result.Check(testkit.Rows("table_with_gen_col_blanks CREATE TABLE `table_with_gen_col_blanks` (\n" +
 		"  `a` int(11) DEFAULT NULL,\n" +
 		"  `b` char(20) GENERATED ALWAYS AS (CAST(`a` AS CHAR)) VIRTUAL DEFAULT NULL\n" +
-		") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin"))
+		") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin"))
 
 	genExprTests := []struct {
 		stmt string
@@ -2296,7 +2296,7 @@ func (s *testDBSuite) TestCheckColumnDefaultValue(c *C) {
 	s.tk.MustQuery(`show create table text_default_text`).Check(testutil.RowsWithSep("|",
 		"text_default_text CREATE TABLE `text_default_text` (\n"+
 			"  `c1` text NOT NULL\n"+
-			") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin",
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 	ctx := s.tk.Se.(sessionctx.Context)
 	is := domain.GetDomain(ctx).InfoSchema()
@@ -2309,7 +2309,7 @@ func (s *testDBSuite) TestCheckColumnDefaultValue(c *C) {
 	s.tk.MustQuery(`show create table text_default_blob`).Check(testutil.RowsWithSep("|",
 		"text_default_blob CREATE TABLE `text_default_blob` (\n"+
 			"  `c1` blob NOT NULL\n"+
-			") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin",
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 	is = domain.GetDomain(ctx).InfoSchema()
 	tblInfo, err = is.TableByName(model.NewCIStr("test"), model.NewCIStr("text_default_blob"))
@@ -2321,7 +2321,7 @@ func (s *testDBSuite) TestCheckColumnDefaultValue(c *C) {
 	s.tk.MustQuery(`show create table text_default_json`).Check(testutil.RowsWithSep("|",
 		"text_default_json CREATE TABLE `text_default_json` (\n"+
 			"  `c1` json NOT NULL DEFAULT 'null'\n"+
-			") ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin",
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin",
 	))
 	is = domain.GetDomain(ctx).InfoSchema()
 	tblInfo, err = is.TableByName(model.NewCIStr("test"), model.NewCIStr("text_default_json"))
@@ -2336,8 +2336,8 @@ func (s *testDBSuite) TestCharacterSetInColumns(c *C) {
 	s.tk.MustExec("use varchar_test")
 	s.tk.MustExec("drop table if exists t")
 	s.tk.MustExec("create table t (c1 int, s1 varchar(10), s2 text)")
-	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name != 'utf8'").Check(testkit.Rows("0"))
-	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name = 'utf8'").Check(testkit.Rows("2"))
+	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name != 'utf8mb4'").Check(testkit.Rows("0"))
+	s.tk.MustQuery("select count(*) from information_schema.columns where table_schema = 'varchar_test' and character_set_name = 'utf8mb4'").Check(testkit.Rows("2"))
 
 	s.tk.MustExec("drop table if exists t5")
 	s.tk.MustExec("create table t5(id int) charset=UTF8;")
@@ -2818,7 +2818,7 @@ func (s *testDBSuite) TestAlterTableDropPartition(c *C) {
 
 	s.tk.MustExec("drop table if exists tr;")
 	s.tk.MustExec(` create table tr(
-		id int, name varchar(50), 
+		id int, name varchar(50),
 		purchased date
 	)
 	partition by range( year(purchased) ) (
@@ -2908,7 +2908,7 @@ func checkPartitionDelRangeDone(c *C, s *testDBSuite, partitionPrefix kv.Key) bo
 	hasOldPartitionData := true
 	for i := 0; i < waitForCleanDataRound; i++ {
 		err := kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
-			it, err := txn.Seek(partitionPrefix)
+			it, err := txn.Iter(partitionPrefix, nil)
 			if err != nil {
 				return err
 			}
@@ -2958,7 +2958,7 @@ func (s *testDBSuite) TestTruncatePartitionAndDropTable(c *C) {
 	// Test truncate table partition.
 	s.tk.MustExec("drop table if exists t3;")
 	s.tk.MustExec(`create table t3(
-		id int, name varchar(50), 
+		id int, name varchar(50),
 		purchased date
 	)
 	partition by range( year(purchased) ) (
@@ -2996,7 +2996,7 @@ func (s *testDBSuite) TestTruncatePartitionAndDropTable(c *C) {
 	// Test drop table partition.
 	s.tk.MustExec("drop table if exists t4;")
 	s.tk.MustExec(`create table t4(
-		id int, name varchar(50), 
+		id int, name varchar(50),
 		purchased date
 	)
 	partition by range( year(purchased) ) (

ddl/ddl_api.go

@@ -65,7 +65,7 @@ func (d *ddl) CreateSchema(ctx sessionctx.Context, schema model.CIStr, charsetIn
 		dbInfo.Charset = charsetInfo.Chs
 		dbInfo.Collate = charsetInfo.Col
 	} else {
-		dbInfo.Charset, dbInfo.Collate = getDefaultCharsetAndCollate()
+		dbInfo.Charset, dbInfo.Collate = charset.GetDefaultCharsetAndCollate()
 	}
 
 	job := &model.Job{
@@ -118,13 +118,6 @@ func checkTooLongIndex(index model.CIStr) error {
 	return nil
 }
 
-func getDefaultCharsetAndCollate() (string, string) {
-	// TODO: TableDefaultCharset-->DatabaseDefaultCharset-->SystemDefaultCharset.
-	// TODO: Change TableOption parser to parse collate.
-	// This is a tmp solution.
-	return "utf8", "utf8_bin"
-}
-
 func setColumnFlagWithConstraint(colMap map[string]*table.Column, v *ast.Constraint) {
 	switch v.Tp {
 	case ast.ConstraintPrimaryKey:
@@ -204,7 +197,7 @@ func setCharsetCollationFlenDecimal(tp *types.FieldType) error {
 	if len(tp.Charset) == 0 {
 		switch tp.Tp {
 		case mysql.TypeString, mysql.TypeVarchar, mysql.TypeVarString, mysql.TypeBlob, mysql.TypeTinyBlob, mysql.TypeMediumBlob, mysql.TypeLongBlob, mysql.TypeEnum, mysql.TypeSet:
-			tp.Charset, tp.Collate = getDefaultCharsetAndCollate()
+			tp.Charset, tp.Collate = charset.GetDefaultCharsetAndCollate()
 		default:
 			tp.Charset = charset.CharsetBin
 			tp.Collate = charset.CharsetBin

ddl/delete_range.go

@@ -14,7 +14,6 @@
 package ddl
 
 import (
-	"bytes"
 	"encoding/hex"
 	"fmt"
 	"math"
@@ -154,7 +153,7 @@ func (dr *delRange) doTask(ctx sessionctx.Context, r util.DelRangeTask) error {
 		finish := true
 		dr.keys = dr.keys[:0]
 		err := kv.RunInNewTxn(dr.store, false, func(txn kv.Transaction) error {
-			iter, err := txn.Seek(oldStartKey)
+			iter, err := txn.Iter(oldStartKey, r.EndKey)
 			if err != nil {
 				return errors.Trace(err)
 			}
@@ -164,10 +163,7 @@ func (dr *delRange) doTask(ctx sessionctx.Context, r util.DelRangeTask) error {
 				if !iter.Valid() {
 					break
 				}
-				finish = bytes.Compare(iter.Key(), r.EndKey) >= 0
-				if finish {
-					break
-				}
+				finish = false
 				dr.keys = append(dr.keys, iter.Key().Clone())
 				newStartKey = iter.Key().Next()