ddl: Support ALTER DATABASE Placement Policy/ DirectOptions

br/pkg/restore/log_client.go

@@ -229,7 +229,7 @@ func (l *LogClient) collectDDLFiles(ctx context.Context) ([]string, error) {
 
 func (l *LogClient) isDBRelatedDDL(ddl *cdclog.MessageDDL) bool {
 	switch ddl.Type {
-	case model.ActionDropSchema, model.ActionCreateSchema, model.ActionModifySchemaCharsetAndCollate:
+	case model.ActionDropSchema, model.ActionCreateSchema, model.ActionModifySchemaCharsetAndCollate, model.ActionModifySchemaDefaultPlacement:
 		return true
 	}
 	return false

ddl/ddl_api.go

@@ -153,31 +153,7 @@ func (d *ddl) CreateSchemaWithInfo(
 	return errors.Trace(err)
 }
 
-func (d *ddl) AlterSchema(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt) (err error) {
-	// Resolve target charset and collation from options.
-	var toCharset, toCollate string
-	for _, val := range stmt.Options {
-		switch val.Tp {
-		case ast.DatabaseOptionCharset:
-			if toCharset == "" {
-				toCharset = val.Value
-			} else if toCharset != val.Value {
-				return ErrConflictingDeclarations.GenWithStackByArgs(toCharset, val.Value)
-			}
-		case ast.DatabaseOptionCollate:
-			info, err := collate.GetCollationByName(val.Value)
-			if err != nil {
-				return errors.Trace(err)
-			}
-			if toCharset == "" {
-				toCharset = info.CharsetName
-			} else if toCharset != info.CharsetName {
-				return ErrConflictingDeclarations.GenWithStackByArgs(toCharset, info.CharsetName)
-			}
-			toCollate = info.Name
-
-		}
-	}
+func (d *ddl) ModifySchemaCharsetAndCollate(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt, toCharset, toCollate string) (err error) {
 	if toCollate == "" {
 		if toCollate, err = charset.GetDefaultCollation(toCharset); err != nil {
 			return errors.Trace(err)
@@ -194,7 +170,6 @@ func (d *ddl) AlterSchema(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt) (
 	if dbInfo.Charset == toCharset && dbInfo.Collate == toCollate {
 		return nil
 	}
-
 	// Do the DDL job.
 	job := &model.Job{
 		SchemaID:   dbInfo.ID,
@@ -208,6 +183,106 @@ func (d *ddl) AlterSchema(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt) (
 	return errors.Trace(err)
 }
 
+func (d *ddl) ModifySchemaDefaultPlacement(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt, placementPolicyRef *model.PolicyRefInfo, directPlacementOpts *model.PlacementSettings) (err error) {
+	dbName := model.NewCIStr(stmt.Name)
+	is := d.GetInfoSchemaWithInterceptor(ctx)
+	dbInfo, ok := is.SchemaByName(dbName)
+	if !ok {
+		return infoschema.ErrDatabaseNotExists.GenWithStackByArgs(dbName.O)
+	}
+
+	if directPlacementOpts != nil && placementPolicyRef != nil {
+		return errors.Trace(ErrPlacementPolicyWithDirectOption.GenWithStackByArgs(placementPolicyRef.Name))
+	}
+
+	if directPlacementOpts != nil {
+		// check the direct placement option compatibility.
+		if err := checkPolicyValidation(directPlacementOpts); err != nil {
+			return errors.Trace(err)
+		}
+	}
+
+	// Do the DDL job.
+	job := &model.Job{
+		SchemaID:   dbInfo.ID,
+		SchemaName: dbInfo.Name.L,
+		Type:       model.ActionModifySchemaDefaultPlacement,
+		BinlogInfo: &model.HistoryInfo{},
+		Args:       []interface{}{placementPolicyRef, directPlacementOpts},
+	}
+	err = d.doDDLJob(ctx, job)
+	err = d.callHookOnChanged(err)
+	return errors.Trace(err)
+}
+
+func (d *ddl) AlterSchema(ctx sessionctx.Context, stmt *ast.AlterDatabaseStmt) (err error) {
+	// Resolve target charset and collation from options.
+	var toCharset, toCollate string
+	var policyName model.CIStr
+	var placementPolicyRef *model.PolicyRefInfo
+	var directPlacementOpts *model.PlacementSettings
+	var isAlterCharsetAndCollate bool
+	var isAlterPlacement bool
+
+	for _, val := range stmt.Options {
+		switch val.Tp {
+		case ast.DatabaseOptionCharset:
+			if toCharset == "" {
+				toCharset = val.Value
+			} else if toCharset != val.Value {
+				return ErrConflictingDeclarations.GenWithStackByArgs(toCharset, val.Value)
+			}
+			isAlterCharsetAndCollate = true
+		case ast.DatabaseOptionCollate:
+			info, errGetCollate := collate.GetCollationByName(val.Value)
+			if errGetCollate != nil {
+				return errors.Trace(errGetCollate)
+			}
+			if toCharset == "" {
+				toCharset = info.CharsetName
+			} else if toCharset != info.CharsetName {
+				return ErrConflictingDeclarations.GenWithStackByArgs(toCharset, info.CharsetName)
+			}
+			toCollate = info.Name
+			isAlterCharsetAndCollate = true
+		case ast.DatabaseOptionPlacementPrimaryRegion, ast.DatabaseOptionPlacementRegions, ast.DatabaseOptionPlacementFollowerCount, ast.DatabaseOptionPlacementVoterCount, ast.DatabaseOptionPlacementLearnerCount, ast.DatabaseOptionPlacementSchedule, ast.DatabaseOptionPlacementConstraints, ast.DatabaseOptionPlacementLeaderConstraints, ast.DatabaseOptionPlacementLearnerConstraints, ast.DatabaseOptionPlacementFollowerConstraints, ast.DatabaseOptionPlacementVoterConstraints:
+			if directPlacementOpts == nil {
+				directPlacementOpts = &model.PlacementSettings{}
+			}
+			err = SetDirectPlacementOpt(directPlacementOpts, ast.PlacementOptionType(val.Tp), val.Value, val.UintValue)
+			if err != nil {
+				return err
+			}
+			isAlterPlacement = true
+		case ast.DatabaseOptionPlacementPolicy:
+			policyName = model.NewCIStr(val.Value)
+			if policyName.L == "default" {
+				placementPolicyRef = nil
+			} else {
+				policy, ok := ctx.GetInfoSchema().(infoschema.InfoSchema).PolicyByName(policyName)
+				if !ok {
+					return errors.Trace(infoschema.ErrPlacementPolicyNotExists.GenWithStackByArgs(policyName))
+				}
+				placementPolicyRef = &model.PolicyRefInfo{ID: policy.ID, Name: policyName}
+			}
+			isAlterPlacement = true
+		}
+	}
+
+	if isAlterCharsetAndCollate {
+		if err = d.ModifySchemaCharsetAndCollate(ctx, stmt, toCharset, toCollate); err != nil {
+			return err
+		}
+	}
+	if isAlterPlacement {
+		if err = d.ModifySchemaDefaultPlacement(ctx, stmt, placementPolicyRef, directPlacementOpts); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (d *ddl) DropSchema(ctx sessionctx.Context, schema model.CIStr) (err error) {
 	is := d.GetInfoSchemaWithInterceptor(ctx)
 	old, ok := is.SchemaByName(schema)
@@ -1822,7 +1897,7 @@ func buildTableInfoWithStmt(ctx sessionctx.Context, s *ast.CreateTableStmt, dbCh
 	}
 
 	if tbInfo.PlacementPolicyRef == nil && tbInfo.DirectPlacementOpts == nil {
-		// Set the defaults from Schema. Note: they are mutual exlusive!
+		// Set the defaults from Schema. Note: they are mutual exclusive!
 		if placementPolicyRef != nil {
 			tbInfo.PlacementPolicyRef = placementPolicyRef
 		} else if directPlacementOpts != nil {

ddl/ddl_worker.go

@@ -744,6 +744,8 @@ func (w *worker) runDDLJob(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64,
 		ver, err = onModifySchemaCharsetAndCollate(t, job)
 	case model.ActionDropSchema:
 		ver, err = onDropSchema(d, t, job)
+	case model.ActionModifySchemaDefaultPlacement:
+		ver, err = onModifySchemaDefaultPlacement(t, job)
 	case model.ActionCreateTable:
 		ver, err = onCreateTable(d, t, job)
 	case model.ActionRepairTable:

ddl/ddl_worker_test.go

@@ -661,6 +661,10 @@ func buildCancelJobTests(firstID int64) []testCancelJob {
 		{act: model.ActionDropIndexes, jobIDs: []int64{firstID + 72}, cancelRetErrs: []error{admin.ErrCannotCancelDDLJob.GenWithStackByArgs(firstID + 72)}, cancelState: model.StateWriteOnly},
 		{act: model.ActionDropIndexes, jobIDs: []int64{firstID + 73}, cancelRetErrs: []error{admin.ErrCannotCancelDDLJob.GenWithStackByArgs(firstID + 73)}, cancelState: model.StateDeleteOnly},
 		{act: model.ActionDropIndexes, jobIDs: []int64{firstID + 74}, cancelRetErrs: []error{admin.ErrCannotCancelDDLJob.GenWithStackByArgs(firstID + 74)}, cancelState: model.StateWriteReorganization},
+
+		// for alter db placement
+		{act: model.ActionModifySchemaDefaultPlacement, jobIDs: []int64{firstID + 75}, cancelRetErrs: noErrs, cancelState: model.StateNone},
+		{act: model.ActionModifySchemaDefaultPlacement, jobIDs: []int64{firstID + 76}, cancelRetErrs: []error{admin.ErrCancelFinishedDDLJob.GenWithStackByArgs(firstID + 76)}, cancelState: model.StatePublic},
 	}
 
 	return tests

ddl/placement_sql_test.go

@@ -23,9 +23,11 @@ import (
 	"github.com/pingcap/parser/model"
 	"github.com/pingcap/tidb/ddl"
 	"github.com/pingcap/tidb/ddl/placement"
+	mysql "github.com/pingcap/tidb/errno"
 	"github.com/pingcap/tidb/session"
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/util/testkit"
+	"github.com/pingcap/tidb/util/testutil"
 )
 
 func (s *testDBSuite6) TestAlterTableAlterPartition(c *C) {
@@ -732,14 +734,14 @@ func (s *testDBSuite6) TestCreateSchemaWithPlacement(c *C) {
 	}()
 
 	tk.MustExec(`CREATE SCHEMA SchemaDirectPlacementTest PRIMARY_REGION='nl' REGIONS = "se,nz" FOLLOWERS=3`)
-	tk.MustQuery("SHOW CREATE SCHEMA schemadirectplacementtest").Check(testkit.Rows("SchemaDirectPlacementTest CREATE DATABASE `SchemaDirectPlacementTest` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ PRIMARY_REGION=\"nl\" REGIONS=\"se,nz\" FOLLOWERS=3"))
+	tk.MustQuery("SHOW CREATE SCHEMA schemadirectplacementtest").Check(testkit.Rows("SchemaDirectPlacementTest CREATE DATABASE `SchemaDirectPlacementTest` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ /*T![placement] PRIMARY_REGION=\"nl\" REGIONS=\"se,nz\" FOLLOWERS=3 */"))
 
 	tk.MustExec(`CREATE PLACEMENT POLICY PolicySchemaTest LEADER_CONSTRAINTS = "[+region=nl]" FOLLOWER_CONSTRAINTS="[+region=se]" FOLLOWERS=4 LEARNER_CONSTRAINTS="[+region=be]" LEARNERS=4`)
 	tk.MustExec(`CREATE PLACEMENT POLICY PolicyTableTest LEADER_CONSTRAINTS = "[+region=tl]" FOLLOWER_CONSTRAINTS="[+region=tf]" FOLLOWERS=2 LEARNER_CONSTRAINTS="[+region=tle]" LEARNERS=1`)
 	tk.MustQuery("SHOW PLACEMENT like 'POLICY %PolicySchemaTest%'").Check(testkit.Rows("POLICY PolicySchemaTest LEADER_CONSTRAINTS=\"[+region=nl]\" FOLLOWERS=4 FOLLOWER_CONSTRAINTS=\"[+region=se]\" LEARNERS=4 LEARNER_CONSTRAINTS=\"[+region=be]\""))
 	tk.MustQuery("SHOW PLACEMENT like 'POLICY %PolicyTableTest%'").Check(testkit.Rows("POLICY PolicyTableTest LEADER_CONSTRAINTS=\"[+region=tl]\" FOLLOWERS=2 FOLLOWER_CONSTRAINTS=\"[+region=tf]\" LEARNERS=1 LEARNER_CONSTRAINTS=\"[+region=tle]\""))
 	tk.MustExec("CREATE SCHEMA SchemaPolicyPlacementTest PLACEMENT POLICY = `PolicySchemaTest`")
-	tk.MustQuery("SHOW CREATE SCHEMA SCHEMAPOLICYPLACEMENTTEST").Check(testkit.Rows("SchemaPolicyPlacementTest CREATE DATABASE `SchemaPolicyPlacementTest` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ PLACEMENT POLICY = `PolicySchemaTest`"))
+	tk.MustQuery("SHOW CREATE SCHEMA SCHEMAPOLICYPLACEMENTTEST").Check(testkit.Rows("SchemaPolicyPlacementTest CREATE DATABASE `SchemaPolicyPlacementTest` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ /*T![placement] PLACEMENT POLICY=`PolicySchemaTest` */"))
 
 	tk.MustExec(`CREATE TABLE SchemaDirectPlacementTest.UseSchemaDefault (a int unsigned primary key, b varchar(255))`)
 	tk.MustQuery(`SHOW CREATE TABLE SchemaDirectPlacementTest.UseSchemaDefault`).Check(testkit.Rows(
@@ -802,3 +804,103 @@ func (s *testDBSuite6) TestCreateSchemaWithPlacement(c *C) {
 	c.Assert(db.DirectPlacementOpts, IsNil)
 	c.Assert(db.PlacementPolicyRef.Name.O, Equals, "PolicySchemaTest")
 }
+
+func (s *testDBSuite6) TestAlterDBPlacement(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("drop database if exists TestAlterDB;")
+	tk.MustExec("create database TestAlterDB;")
+	tk.MustExec("use TestAlterDB")
+	tk.MustExec("drop placement policy if exists x")
+	tk.MustExec("drop placement policy if exists y")
+	tk.MustExec("create placement policy x PRIMARY_REGION=\"cn-east-1\";")
+	tk.MustExec("create placement policy y PRIMARY_REGION=\"cn-east-2\";")
+
+	// Policy Test
+	tk.MustExec("ALTER DATABASE TestAlterDB PLACEMENT POLICY=`x`;")
+	// Test for Show Create Database
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PLACEMENT POLICY=`x` */",
+	))
+	// Test for Alter Placement Policy affect table created.
+	tk.MustExec("create table t(a int);")
+	tk.MustQuery(`show create table t`).Check(testutil.RowsWithSep("|",
+		"t CREATE TABLE `t` (\n"+
+			"  `a` int(11) DEFAULT NULL\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin "+
+			"/*T![placement] PLACEMENT POLICY=`x` */",
+	))
+	// Test for Alter Default Placement Policy, And will not update the old table options.
+	tk.MustExec("ALTER DATABASE TestAlterDB DEFAULT PLACEMENT POLICY=`y`;")
+	tk.MustExec("create table t2(a int);")
+	tk.MustQuery(`show create table t`).Check(testutil.RowsWithSep("|",
+		"t CREATE TABLE `t` (\n"+
+			"  `a` int(11) DEFAULT NULL\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin "+
+			"/*T![placement] PLACEMENT POLICY=`x` */",
+	))
+	tk.MustQuery(`show create table t2`).Check(testutil.RowsWithSep("|",
+		"t2 CREATE TABLE `t2` (\n"+
+			"  `a` int(11) DEFAULT NULL\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin "+
+			"/*T![placement] PLACEMENT POLICY=`y` */",
+	))
+
+	// Reset Test
+	tk.MustExec("drop database if exists TestAlterDB;")
+	tk.MustExec("create database TestAlterDB;")
+	tk.MustExec("use TestAlterDB")
+
+	// DirectOption Test
+	tk.MustExec("ALTER DATABASE TestAlterDB PRIMARY_REGION=\"se\" FOLLOWERS=2;")
+	// Test for Show Create Database
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PRIMARY_REGION=\"se\" FOLLOWERS=2 */",
+	))
+	// Test for Alter Placement Rule affect table created.
+	tk.MustExec("create table t3(a int);")
+	tk.MustQuery(`show create table t3`).Check(testutil.RowsWithSep("|",
+		"t3 CREATE TABLE `t3` (\n"+
+			"  `a` int(11) DEFAULT NULL\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin "+
+			"/*T![placement] PRIMARY_REGION=\"se\" FOLLOWERS=2 */",
+	))
+	// Test for override default option
+	tk.MustExec("create table t4(a int) PLACEMENT POLICY=\"x\";")
+	tk.MustQuery(`show create table t4`).Check(testutil.RowsWithSep("|",
+		"t4 CREATE TABLE `t4` (\n"+
+			"  `a` int(11) DEFAULT NULL\n"+
+			") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin "+
+			"/*T![placement] PLACEMENT POLICY=`x` */",
+	))
+
+	// Hybrid Test
+	// Test for alter both policy and  direct options.
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PRIMARY_REGION=\"se\" FOLLOWERS=2 */",
+	))
+	tk.MustGetErrCode("ALTER DATABASE TestAlterDB PLACEMENT POLICY=`x` FOLLOWERS=2;", mysql.ErrPlacementPolicyWithDirectOption)
+	tk.MustGetErrCode("ALTER DATABASE TestAlterDB DEFAULT PLACEMENT POLICY=`y` PRIMARY_REGION=\"se\" FOLLOWERS=2;", mysql.ErrPlacementPolicyWithDirectOption)
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PRIMARY_REGION=\"se\" FOLLOWERS=2 */",
+	))
+	// Test for change direct options to policy.
+	tk.MustExec("ALTER DATABASE TestAlterDB PLACEMENT POLICY=`x`;")
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PLACEMENT POLICY=`x` */",
+	))
+	// Test for change policy to direct options.
+	tk.MustExec("ALTER DATABASE TestAlterDB PRIMARY_REGION=\"se\" FOLLOWERS=2;")
+	tk.MustQuery(`show create database TestAlterDB`).Check(testutil.RowsWithSep("|",
+		"TestAlterDB CREATE DATABASE `TestAlterDB` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ "+
+			"/*T![placement] PRIMARY_REGION=\"se\" FOLLOWERS=2 */",
+	))
+
+	tk.MustExec(`DROP DATABASE IF EXISTS TestAlterDB;`)
+	tk.MustExec("drop placement policy if exists x")
+	tk.MustExec("drop placement policy if exists y")
+}

ddl/rollingback.go

@@ -476,7 +476,7 @@ func convertJob2RollbackJob(w *worker, d *ddlCtx, t *meta.Meta, job *model.Job)
 		model.ActionModifyTableCharsetAndCollate, model.ActionTruncateTablePartition,
 		model.ActionModifySchemaCharsetAndCollate, model.ActionRepairTable,
 		model.ActionModifyTableAutoIdCache, model.ActionAlterIndexVisibility,
-		model.ActionExchangeTablePartition:
+		model.ActionExchangeTablePartition, model.ActionModifySchemaDefaultPlacement:
 		ver, err = cancelOnlyNotHandledJob(job)
 	default:
 		job.State = model.JobStateCancelled

ddl/schema.go

@@ -140,6 +140,39 @@ func onModifySchemaCharsetAndCollate(t *meta.Meta, job *model.Job) (ver int64, _
 	return ver, nil
 }
 
+func onModifySchemaDefaultPlacement(t *meta.Meta, job *model.Job) (ver int64, _ error) {
+	var placementPolicyRef *model.PolicyRefInfo
+	var directPlacementOpts *model.PlacementSettings
+	if err := job.DecodeArgs(&placementPolicyRef, &directPlacementOpts); err != nil {
+		job.State = model.JobStateCancelled
+		return ver, errors.Trace(err)
+	}
+
+	dbInfo, err := checkSchemaExistAndCancelNotExistJob(t, job)
+	if err != nil {
+		return ver, errors.Trace(err)
+	}
+
+	// Notice: dbInfo.DirectPlacementOpts and dbInfo.PlacementPolicyRef can not be both not nil.
+	if (dbInfo.DirectPlacementOpts == directPlacementOpts) && (dbInfo.PlacementPolicyRef == placementPolicyRef) {
+		job.FinishDBJob(model.JobStateDone, model.StatePublic, ver, dbInfo)
+		return ver, nil
+	}
+
+	// If placementPolicyRef and directPlacementOpts are both nil, And placement of dbInfo is not nil, it will remove all placement options.
+	dbInfo.PlacementPolicyRef = placementPolicyRef
+	dbInfo.DirectPlacementOpts = directPlacementOpts
+
+	if err = t.UpdateDatabase(dbInfo); err != nil {
+		return ver, errors.Trace(err)
+	}
+	if ver, err = updateSchemaVersion(t, job); err != nil {
+		return ver, errors.Trace(err)
+	}
+	job.FinishDBJob(model.JobStateDone, model.StatePublic, ver, dbInfo)
+	return ver, nil
+}
+
 func onDropSchema(d *ddlCtx, t *meta.Meta, job *model.Job) (ver int64, _ error) {
 	dbInfo, err := checkSchemaExistAndCancelNotExistJob(t, job)
 	if err != nil {

executor/show.go

@@ -1071,7 +1071,7 @@ func ConstructResultOfShowCreateTable(ctx sessionctx.Context, tableInfo *model.T
 	}
 
 	if tableInfo.PlacementPolicyRef != nil {
-		fmt.Fprintf(buf, " /*T![placement] PLACEMENT POLICY=`%s` */", tableInfo.PlacementPolicyRef.Name.String())
+		fmt.Fprintf(buf, " /*T![placement] PLACEMENT POLICY=%s */", stringutil.Escape(tableInfo.PlacementPolicyRef.Name.String(), sqlMode))
 	}
 
 	// add direct placement info here
@@ -1331,12 +1331,12 @@ func ConstructResultOfShowCreateDatabase(ctx sessionctx.Context, dbInfo *model.D
 	}
 	// MySQL 5.7 always show the charset info but TiDB may ignore it, which makes a slight difference. We keep this
 	// behavior unchanged because it is trivial enough.
-	if dbInfo.DirectPlacementOpts != nil {
-		fmt.Fprintf(buf, " %s", dbInfo.DirectPlacementOpts)
-	}
+
 	if dbInfo.PlacementPolicyRef != nil {
-		fmt.Fprintf(buf, " PLACEMENT POLICY = %s", stringutil.Escape(dbInfo.PlacementPolicyRef.Name.O, sqlMode))
+		fmt.Fprintf(buf, " /*T![placement] PLACEMENT POLICY=%s */", stringutil.Escape(dbInfo.PlacementPolicyRef.Name.String(), sqlMode))
 	}
+	// add direct placement info here
+	appendDirectPlacementInfo(dbInfo.DirectPlacementOpts, buf)
 	return nil
 }