diff --git a/ddl/ddl_db_test.go b/ddl/ddl_db_test.go
index 032005b653e0f..8cd23af585df8 100644
--- a/ddl/ddl_db_test.go
+++ b/ddl/ddl_db_test.go
@@ -26,7 +26,6 @@ import (
 	gofail "github.com/coreos/gofail/runtime"
 	"github.com/juju/errors"
 	. "github.com/pingcap/check"
-	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/ddl"
 	"github.com/pingcap/tidb/domain"
 	"github.com/pingcap/tidb/infoschema"
@@ -1932,91 +1931,3 @@ func (s *testDBSuite) TestAddIndexFailed(c *C) {
 	tk.MustExec("admin check index t idx_b")
 	tk.MustExec("admin check table t")
 }
-
-func (s *testDBSuite) getHistoryDDLJob(id int64) (*model.Job, error) {
-	var job *model.Job
-
-	err := kv.RunInNewTxn(s.store, false, func(txn kv.Transaction) error {
-		t := meta.NewMeta(txn)
-		var err1 error
-		job, err1 = t.GetHistoryDDLJob(id)
-		return errors.Trace(err1)
-	})
-
-	return job, errors.Trace(err)
-}
-
-func (s *testDBSuite) TestBackwardCompatibility(c *C) {
-	tk := testkit.NewTestKit(c, s.store)
-	tk.MustExec("create database if not exists test_backward_compatibility")
-	defer tk.MustExec("drop database test_backward_compatibility")
-	tk.MustExec("use test_backward_compatibility")
-	tk.MustExec("create table t(a int primary key, b int)")
-	for i := 0; i < 200; i++ {
-		tk.MustExec(fmt.Sprintf("insert into t values(%v, %v)", i, i))
-	}
-
-	// alter table t add index idx_b(b);
-	is := s.dom.InfoSchema()
-	schemaName := model.NewCIStr("test_backward_compatibility")
-	tableName := model.NewCIStr("t")
-	schema, ok := is.SchemaByName(schemaName)
-	c.Assert(ok, IsTrue)
-	tbl, err := is.TableByName(schemaName, tableName)
-	c.Assert(err, IsNil)
-
-	// Split the table.
-	s.cluster.SplitTable(s.mvccStore, tbl.Meta().ID, 100)
-
-	unique := false
-	indexName := model.NewCIStr("idx_b")
-	idxColName := &ast.IndexColName{
-		Column: &ast.ColumnName{
-			Schema: schemaName,
-			Table:  tableName,
-			Name:   model.NewCIStr("b"),
-		},
-		Length: types.UnspecifiedLength,
-	}
-	idxColNames := []*ast.IndexColName{idxColName}
-	var indexOption *ast.IndexOption
-	job := &model.Job{
-		SchemaID:   schema.ID,
-		TableID:    tbl.Meta().ID,
-		Type:       model.ActionAddIndex,
-		BinlogInfo: &model.HistoryInfo{},
-		Args:       []interface{}{unique, indexName, idxColNames, indexOption},
-	}
-	txn, err := s.store.Begin()
-	c.Assert(err, IsNil)
-	t := meta.NewMeta(txn)
-	job.ID, err = t.GenGlobalID()
-	c.Assert(err, IsNil)
-	job.Version = 1
-	job.StartTS = txn.StartTS()
-
-	// Simulate old TiDB init the add index job, old TiDB will not init the model.Job.ReorgMeta field,
-	// if we set job.SnapshotVer here, can simulate the behavior.
-	job.SnapshotVer = txn.StartTS()
-	err = t.EnQueueDDLJob(job)
-	c.Assert(err, IsNil)
-	err = txn.Commit(context.Background())
-	c.Assert(err, IsNil)
-	ticker := time.NewTicker(s.lease)
-	for range ticker.C {
-		historyJob, err := s.getHistoryDDLJob(job.ID)
-		c.Assert(err, IsNil)
-		if historyJob == nil {
-
-			continue
-		}
-		c.Assert(historyJob.Error, IsNil)
-
-		if historyJob.IsSynced() {
-			break
-		}
-	}
-
-	// finished add index
-	tk.MustExec("admin check index t idx_b")
-}