diff --git a/ast/misc.go b/ast/misc.go
index 6d8afbeea1569..27ec5e9233ee5 100644
--- a/ast/misc.go
+++ b/ast/misc.go
@@ -13,7 +13,14 @@
 
 package ast
 
-import "github.com/pingcap/tidb/mysql"
+import (
+	"fmt"
+
+	"github.com/pingcap/tidb/context"
+	"github.com/pingcap/tidb/model"
+	"github.com/pingcap/tidb/mysql"
+	"github.com/pingcap/tidb/sessionctx/db"
+)
 
 var (
 	_ StmtNode = &AdminStmt{}
@@ -473,3 +480,28 @@ func (n *GrantStmt) Accept(v Visitor) (Node, bool) {
 	}
 	return v.Leave(n)
 }
+
+// Ident is the table identifier composed of schema name and table name.
+type Ident struct {
+	Schema model.CIStr
+	Name   model.CIStr
+}
+
+// Full returns an Ident which set schema to the current schema if it is empty.
+func (i Ident) Full(ctx context.Context) (full Ident) {
+	full.Name = i.Name
+	if i.Schema.O != "" {
+		full.Schema = i.Schema
+	} else {
+		full.Schema = model.NewCIStr(db.GetCurrentSchema(ctx))
+	}
+	return
+}
+
+// String implements fmt.Stringer interface
+func (i Ident) String() string {
+	if i.Schema.O == "" {
+		return i.Name.O
+	}
+	return fmt.Sprintf("%s.%s", i.Schema, i.Name)
+}
diff --git a/ddl/alter.go b/ddl/alter.go
deleted file mode 100644
index 5cfcb0b7b7ab8..0000000000000
--- a/ddl/alter.go
+++ /dev/null
@@ -1,99 +0,0 @@
-// Copyright 2015 PingCAP, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package ddl
-
-import (
-	"fmt"
-
-	"github.com/pingcap/tidb/parser/coldef"
-)
-
-// AlterTableSpecification.Action types.
-// TODO: Add more actions.
-const (
-	AlterTableOpt int = iota + 1
-	AlterAddColumn
-	AlterAddConstr
-	AlterDropColumn
-	AlterDropPrimaryKey
-	AlterDropIndex
-	AlterDropForeignKey
-)
-
-// ColumnPosition Types.
-const (
-	ColumnPositionNone int = iota
-	ColumnPositionFirst
-	ColumnPositionAfter
-)
-
-// ColumnPosition represents the position of the newly added column.
-type ColumnPosition struct {
-	// ColumnPositionNone | ColumnPositionFirst | ColumnPositionAfter
-	Type int
-	// RelativeColumn is the column which is before the newly added column if type is ColumnPositionAfter.
-	RelativeColumn string
-}
-
-// String implements fmt.Stringer.
-func (cp *ColumnPosition) String() string {
-	switch cp.Type {
-	case ColumnPositionFirst:
-		return "FIRST"
-	case ColumnPositionAfter:
-		return fmt.Sprintf("AFTER %s", cp.RelativeColumn)
-	default:
-		return ""
-	}
-}
-
-// AlterSpecification alter table specification.
-type AlterSpecification struct {
-	Action     int
-	Name       string
-	Constraint *coldef.TableConstraint
-	TableOpts  []*coldef.TableOpt
-	Column     *coldef.ColumnDef
-	Position   *ColumnPosition
-}
-
-// String implements fmt.Stringer.
-func (as *AlterSpecification) String() string {
-	switch as.Action {
-	case AlterTableOpt:
-		// TODO: Finish this
-		return ""
-	case AlterAddConstr:
-		if as.Constraint != nil {
-			return fmt.Sprintf("ADD %s", as.Constraint.String())
-		}
-		return ""
-	case AlterDropColumn:
-		return fmt.Sprintf("DROP COLUMN %s", as.Name)
-	case AlterDropPrimaryKey:
-		return fmt.Sprintf("DROP PRIMARY KEY")
-	case AlterDropIndex:
-		return fmt.Sprintf("DROP INDEX %s", as.Name)
-	case AlterDropForeignKey:
-		return fmt.Sprintf("DROP FOREIGN KEY %s", as.Name)
-	case AlterAddColumn:
-		ps := as.Position.String()
-		if len(ps) > 0 {
-			return fmt.Sprintf("ADD Column %s %s", as.Column.String(), ps)
-		}
-		return fmt.Sprintf("ADD Column %s", as.Column.String())
-	default:
-		return ""
-	}
-}
diff --git a/ddl/alter_test.go b/ddl/alter_test.go
deleted file mode 100644
index daa6b5f5fffb3..0000000000000
--- a/ddl/alter_test.go
+++ /dev/null
@@ -1,76 +0,0 @@
-// Copyright 2015 PingCAP, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package ddl
-
-import (
-	. "github.com/pingcap/check"
-	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
-	"github.com/pingcap/tidb/util/types"
-)
-
-func (s *testDDLSuite) TestAlterSpecification(c *C) {
-	tbl := []*AlterSpecification{
-		{
-			Action: AlterTableOpt,
-		},
-		{
-			Action: AlterDropColumn,
-			Name:   "c1",
-		},
-		{Action: AlterDropPrimaryKey},
-		{Action: AlterDropForeignKey,
-			Name: "c"},
-		{Action: AlterDropIndex,
-			Name: "index_c"},
-		{Action: AlterAddConstr,
-			Constraint: nil},
-		{Action: AlterAddConstr,
-			Constraint: &coldef.TableConstraint{
-				Tp: coldef.ConstrPrimaryKey,
-				Keys: []*coldef.IndexColName{
-					{
-						ColumnName: "a",
-						Length:     10,
-					},
-				},
-			}},
-		{Action: AlterAddColumn,
-			Column: &coldef.ColumnDef{
-				Name: "c",
-				Tp:   types.NewFieldType(mysql.TypeLong),
-			},
-			Position: &ColumnPosition{}},
-		{Action: AlterAddColumn,
-			Column: &coldef.ColumnDef{
-				Name: "c",
-				Tp:   types.NewFieldType(mysql.TypeLong),
-			},
-			Position: &ColumnPosition{Type: ColumnPositionFirst}},
-		{Action: AlterAddColumn,
-			Column: &coldef.ColumnDef{
-				Name: "c",
-				Tp:   types.NewFieldType(mysql.TypeLong),
-			},
-			Position: &ColumnPosition{Type: ColumnPositionAfter,
-				RelativeColumn: "c"}},
-
-		// Invalid action returns empty string
-		{Action: -1},
-	}
-
-	for _, spec := range tbl {
-		c.Assert(len(spec.String()), GreaterEqual, 0)
-	}
-}
diff --git a/ddl/column.go b/ddl/column.go
index 5a1a91a2ed982..6cfa3aed69258 100644
--- a/ddl/column.go
+++ b/ddl/column.go
@@ -16,6 +16,7 @@ package ddl
 import (
 	"github.com/juju/errors"
 	"github.com/ngaut/log"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
@@ -55,16 +56,16 @@ func (d *ddl) adjustColumnOffset(columns []*model.ColumnInfo, indices []*model.I
 	}
 }
 
-func (d *ddl) addColumn(tblInfo *model.TableInfo, colInfo *model.ColumnInfo, pos *ColumnPosition) (*model.ColumnInfo, int, error) {
+func (d *ddl) addColumn(tblInfo *model.TableInfo, colInfo *model.ColumnInfo, pos *ast.ColumnPosition) (*model.ColumnInfo, int, error) {
 	// Check column name duplicate.
 	cols := tblInfo.Columns
 	position := len(cols)
 
 	// Get column position.
-	if pos.Type == ColumnPositionFirst {
+	if pos.Tp == ast.ColumnPositionFirst {
 		position = 0
-	} else if pos.Type == ColumnPositionAfter {
-		c := findCol(cols, pos.RelativeColumn)
+	} else if pos.Tp == ast.ColumnPositionAfter {
+		c := findCol(cols, pos.RelativeColumn.Name.L)
 		if c == nil {
 			return nil, 0, errors.Errorf("No such column: %v", pos.RelativeColumn)
 		}
@@ -96,7 +97,7 @@ func (d *ddl) onAddColumn(t *meta.Meta, job *model.Job) error {
 	}
 
 	col := &model.ColumnInfo{}
-	pos := &ColumnPosition{}
+	pos := &ast.ColumnPosition{}
 	offset := 0
 	err = job.DecodeArgs(col, pos, &offset)
 	if err != nil {
diff --git a/ddl/column_test.go b/ddl/column_test.go
index c95288e660aa0..0962fcaf3517c 100644
--- a/ddl/column_test.go
+++ b/ddl/column_test.go
@@ -17,6 +17,7 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/kv"
@@ -59,7 +60,7 @@ func (s *testColumnSuite) TearDownSuite(c *C) {
 }
 
 func testCreateColumn(c *C, ctx context.Context, d *ddl, dbInfo *model.DBInfo, tblInfo *model.TableInfo,
-	colName string, pos *ColumnPosition, defaultValue interface{}) *model.Job {
+	colName string, pos *ast.ColumnPosition, defaultValue interface{}) *model.Job {
 	col := &model.ColumnInfo{
 		Name:         model.NewCIStr(colName),
 		Offset:       len(tblInfo.Columns),
@@ -133,7 +134,7 @@ func (s *testColumnSuite) TestColumn(c *C) {
 
 	c.Assert(column.FindCol(t.Cols(), "c4"), IsNil)
 
-	job := testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c4", &ColumnPosition{Type: ColumnPositionAfter, RelativeColumn: "c3"}, 100)
+	job := testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c4", &ast.ColumnPosition{Tp: ast.ColumnPositionAfter, RelativeColumn: &ast.ColumnName{Name: model.NewCIStr("c3")}}, 100)
 	testCheckJobDone(c, s.d, job, true)
 
 	t = testGetTable(c, s.d, s.dbInfo.ID, tblInfo.ID)
@@ -171,7 +172,7 @@ func (s *testColumnSuite) TestColumn(c *C) {
 	c.Assert(values, HasLen, 3)
 	c.Assert(values[2].GetInt64(), Equals, int64(13))
 
-	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c4", &ColumnPosition{Type: ColumnPositionNone}, 111)
+	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c4", &ast.ColumnPosition{Tp: ast.ColumnPositionNone}, 111)
 	testCheckJobDone(c, s.d, job, true)
 
 	t = testGetTable(c, s.d, s.dbInfo.ID, tblInfo.ID)
@@ -181,7 +182,7 @@ func (s *testColumnSuite) TestColumn(c *C) {
 	c.Assert(values, HasLen, 4)
 	c.Assert(values[3].GetInt64(), Equals, int64(111))
 
-	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c5", &ColumnPosition{Type: ColumnPositionNone}, 101)
+	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c5", &ast.ColumnPosition{Tp: ast.ColumnPositionNone}, 101)
 	testCheckJobDone(c, s.d, job, true)
 
 	t = testGetTable(c, s.d, s.dbInfo.ID, tblInfo.ID)
@@ -191,7 +192,7 @@ func (s *testColumnSuite) TestColumn(c *C) {
 	c.Assert(values, HasLen, 5)
 	c.Assert(values[4].GetInt64(), Equals, int64(101))
 
-	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c6", &ColumnPosition{Type: ColumnPositionFirst}, 202)
+	job = testCreateColumn(c, ctx, s.d, s.dbInfo, tblInfo, "c6", &ast.ColumnPosition{Tp: ast.ColumnPositionFirst}, 202)
 	testCheckJobDone(c, s.d, job, true)
 
 	t = testGetTable(c, s.d, s.dbInfo.ID, tblInfo.ID)
@@ -598,7 +599,7 @@ func (s *testColumnSuite) TestAddColumn(c *C) {
 	d.close()
 	d.start()
 
-	job := testCreateColumn(c, ctx, d, s.dbInfo, tblInfo, colName, &ColumnPosition{Type: ColumnPositionNone}, defaultColValue)
+	job := testCreateColumn(c, ctx, d, s.dbInfo, tblInfo, colName, &ast.ColumnPosition{Tp: ast.ColumnPositionNone}, defaultColValue)
 	testCheckJobDone(c, d, job, true)
 
 	_, err = ctx.GetTxn(true)
diff --git a/ddl/ddl.go b/ddl/ddl.go
index 6abc7ae2b6890..6c2bdadcf79a6 100644
--- a/ddl/ddl.go
+++ b/ddl/ddl.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/juju/errors"
 	"github.com/ngaut/log"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/evaluator"
@@ -33,9 +34,7 @@ import (
 	"github.com/pingcap/tidb/meta"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/sessionctx/variable"
-	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/util/charset"
 	"github.com/pingcap/tidb/util/types"
 	"github.com/twinj/uuid"
@@ -43,14 +42,14 @@ import (
 
 // DDL is responsible for updating schema in data store and maintaining in-memory InfoSchema cache.
 type DDL interface {
-	CreateSchema(ctx context.Context, name model.CIStr, charsetInfo *coldef.CharsetOpt) error
+	CreateSchema(ctx context.Context, name model.CIStr, charsetInfo *ast.CharsetOpt) error
 	DropSchema(ctx context.Context, schema model.CIStr) error
-	CreateTable(ctx context.Context, ident table.Ident, cols []*coldef.ColumnDef, constrs []*coldef.TableConstraint) error
-	DropTable(ctx context.Context, tableIdent table.Ident) (err error)
-	CreateIndex(ctx context.Context, tableIdent table.Ident, unique bool, indexName model.CIStr, columnNames []*coldef.IndexColName) error
-	DropIndex(ctx context.Context, tableIdent table.Ident, indexName model.CIStr) error
+	CreateTable(ctx context.Context, ident ast.Ident, cols []*ast.ColumnDef, constrs []*ast.Constraint) error
+	DropTable(ctx context.Context, tableIdent ast.Ident) (err error)
+	CreateIndex(ctx context.Context, tableIdent ast.Ident, unique bool, indexName model.CIStr, columnNames []*ast.IndexColName) error
+	DropIndex(ctx context.Context, tableIdent ast.Ident, indexName model.CIStr) error
 	GetInformationSchema() infoschema.InfoSchema
-	AlterTable(ctx context.Context, tableIdent table.Ident, spec []*AlterSpecification) error
+	AlterTable(ctx context.Context, tableIdent ast.Ident, spec []*ast.AlterTableSpec) error
 	// SetLease will reset the lease time for online DDL change, it is a very dangerous function and you must guarantee that
 	// all servers have the same lease time.
 	SetLease(lease time.Duration)
@@ -244,7 +243,7 @@ func (d *ddl) genGlobalID() (int64, error) {
 	return globalID, errors.Trace(err)
 }
 
-func (d *ddl) CreateSchema(ctx context.Context, schema model.CIStr, charsetInfo *coldef.CharsetOpt) (err error) {
+func (d *ddl) CreateSchema(ctx context.Context, schema model.CIStr, charsetInfo *ast.CharsetOpt) (err error) {
 	is := d.GetInformationSchema()
 	_, ok := is.SchemaByName(schema)
 	if ok {
@@ -300,11 +299,11 @@ func getDefaultCharsetAndCollate() (string, string) {
 	return "utf8", "utf8_unicode_ci"
 }
 
-func setColumnFlagWithConstraint(colMap map[string]*column.Col, v *coldef.TableConstraint) {
+func setColumnFlagWithConstraint(colMap map[string]*column.Col, v *ast.Constraint) {
 	switch v.Tp {
-	case coldef.ConstrPrimaryKey:
+	case ast.ConstraintPrimaryKey:
 		for _, key := range v.Keys {
-			c, ok := colMap[strings.ToLower(key.ColumnName)]
+			c, ok := colMap[key.Column.Name.L]
 			if !ok {
 				// TODO: table constraint on unknown column.
 				continue
@@ -313,9 +312,9 @@ func setColumnFlagWithConstraint(colMap map[string]*column.Col, v *coldef.TableC
 			// Primary key can not be NULL.
 			c.Flag |= mysql.NotNullFlag
 		}
-	case coldef.ConstrUniq, coldef.ConstrUniqIndex, coldef.ConstrUniqKey:
+	case ast.ConstraintUniq, ast.ConstraintUniqIndex, ast.ConstraintUniqKey:
 		for i, key := range v.Keys {
-			c, ok := colMap[strings.ToLower(key.ColumnName)]
+			c, ok := colMap[key.Column.Name.L]
 			if !ok {
 				// TODO: table constraint on unknown column.
 				continue
@@ -332,9 +331,9 @@ func setColumnFlagWithConstraint(colMap map[string]*column.Col, v *coldef.TableC
 				}
 			}
 		}
-	case coldef.ConstrKey, coldef.ConstrIndex:
+	case ast.ConstraintKey, ast.ConstraintIndex:
 		for i, key := range v.Keys {
-			c, ok := colMap[strings.ToLower(key.ColumnName)]
+			c, ok := colMap[key.Column.Name.L]
 			if !ok {
 				// TODO: table constraint on unknown column.
 				continue
@@ -347,8 +346,8 @@ func setColumnFlagWithConstraint(colMap map[string]*column.Col, v *coldef.TableC
 	}
 }
 
-func (d *ddl) buildColumnsAndConstraints(ctx context.Context, colDefs []*coldef.ColumnDef,
-	constraints []*coldef.TableConstraint) ([]*column.Col, []*coldef.TableConstraint, error) {
+func (d *ddl) buildColumnsAndConstraints(ctx context.Context, colDefs []*ast.ColumnDef,
+	constraints []*ast.Constraint) ([]*column.Col, []*ast.Constraint, error) {
 	var cols []*column.Col
 	colMap := map[string]*column.Col{}
 	for i, colDef := range colDefs {
@@ -359,7 +358,7 @@ func (d *ddl) buildColumnsAndConstraints(ctx context.Context, colDefs []*coldef.
 		col.State = model.StatePublic
 		constraints = append(constraints, cts...)
 		cols = append(cols, col)
-		colMap[strings.ToLower(colDef.Name)] = col
+		colMap[colDef.Name.Name.L] = col
 	}
 	// traverse table Constraints and set col.flag
 	for _, v := range constraints {
@@ -369,7 +368,7 @@ func (d *ddl) buildColumnsAndConstraints(ctx context.Context, colDefs []*coldef.
 }
 
 func (d *ddl) buildColumnAndConstraint(ctx context.Context, offset int,
-	colDef *coldef.ColumnDef) (*column.Col, []*coldef.TableConstraint, error) {
+	colDef *ast.ColumnDef) (*column.Col, []*ast.Constraint, error) {
 	// Set charset.
 	if len(colDef.Tp.Charset) == 0 {
 		switch colDef.Tp.Tp {
@@ -395,12 +394,12 @@ func (d *ddl) buildColumnAndConstraint(ctx context.Context, offset int,
 }
 
 // columnDefToCol converts ColumnDef to Col and TableConstraints.
-func columnDefToCol(ctx context.Context, offset int, colDef *coldef.ColumnDef) (*column.Col, []*coldef.TableConstraint, error) {
-	constraints := []*coldef.TableConstraint{}
+func columnDefToCol(ctx context.Context, offset int, colDef *ast.ColumnDef) (*column.Col, []*ast.Constraint, error) {
+	constraints := []*ast.Constraint{}
 	col := &column.Col{
 		ColumnInfo: model.ColumnInfo{
 			Offset:    offset,
-			Name:      model.NewCIStr(colDef.Name),
+			Name:      colDef.Name.Name,
 			FieldType: *colDef.Tp,
 		},
 	}
@@ -422,45 +421,45 @@ func columnDefToCol(ctx context.Context, offset int, colDef *coldef.ColumnDef) (
 
 	setOnUpdateNow := false
 	hasDefaultValue := false
-	if colDef.Constraints != nil {
-		keys := []*coldef.IndexColName{
+	if colDef.Options != nil {
+		keys := []*ast.IndexColName{
 			{
-				colDef.Name,
-				colDef.Tp.Flen,
+				Column: colDef.Name,
+				Length: colDef.Tp.Flen,
 			},
 		}
-		for _, v := range colDef.Constraints {
+		for _, v := range colDef.Options {
 			switch v.Tp {
-			case coldef.ConstrNotNull:
+			case ast.ColumnOptionNotNull:
 				col.Flag |= mysql.NotNullFlag
-			case coldef.ConstrNull:
+			case ast.ColumnOptionNull:
 				col.Flag &= ^uint(mysql.NotNullFlag)
 				removeOnUpdateNowFlag(col)
-			case coldef.ConstrAutoIncrement:
+			case ast.ColumnOptionAutoIncrement:
 				col.Flag |= mysql.AutoIncrementFlag
-			case coldef.ConstrPrimaryKey:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrPrimaryKey, Keys: keys}
+			case ast.ColumnOptionPrimaryKey:
+				constraint := &ast.Constraint{Tp: ast.ConstraintPrimaryKey, Keys: keys}
 				constraints = append(constraints, constraint)
 				col.Flag |= mysql.PriKeyFlag
-			case coldef.ConstrUniq:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrUniq, ConstrName: colDef.Name, Keys: keys}
+			case ast.ColumnOptionUniq:
+				constraint := &ast.Constraint{Tp: ast.ConstraintUniq, Name: colDef.Name.Name.O, Keys: keys}
 				constraints = append(constraints, constraint)
 				col.Flag |= mysql.UniqueKeyFlag
-			case coldef.ConstrIndex:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrIndex, ConstrName: colDef.Name, Keys: keys}
+			case ast.ColumnOptionIndex:
+				constraint := &ast.Constraint{Tp: ast.ConstraintIndex, Name: colDef.Name.Name.O, Keys: keys}
 				constraints = append(constraints, constraint)
-			case coldef.ConstrUniqIndex:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrUniqIndex, ConstrName: colDef.Name, Keys: keys}
+			case ast.ColumnOptionUniqIndex:
+				constraint := &ast.Constraint{Tp: ast.ConstraintUniqIndex, Name: colDef.Name.Name.O, Keys: keys}
 				constraints = append(constraints, constraint)
 				col.Flag |= mysql.UniqueKeyFlag
-			case coldef.ConstrKey:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrKey, ConstrName: colDef.Name, Keys: keys}
+			case ast.ColumnOptionKey:
+				constraint := &ast.Constraint{Tp: ast.ConstraintKey, Name: colDef.Name.Name.O, Keys: keys}
 				constraints = append(constraints, constraint)
-			case coldef.ConstrUniqKey:
-				constraint := &coldef.TableConstraint{Tp: coldef.ConstrUniqKey, ConstrName: colDef.Name, Keys: keys}
+			case ast.ColumnOptionUniqKey:
+				constraint := &ast.Constraint{Tp: ast.ConstraintUniqKey, Name: colDef.Name.Name.O, Keys: keys}
 				constraints = append(constraints, constraint)
 				col.Flag |= mysql.UniqueKeyFlag
-			case coldef.ConstrDefaultValue:
+			case ast.ColumnOptionDefaultValue:
 				value, err := getDefaultValue(ctx, v, colDef.Tp.Tp, colDef.Tp.Decimal)
 				if err != nil {
 					return nil, nil, errors.Errorf("invalid default value - %s", errors.Trace(err))
@@ -468,16 +467,14 @@ func columnDefToCol(ctx context.Context, offset int, colDef *coldef.ColumnDef) (
 				col.DefaultValue = value
 				hasDefaultValue = true
 				removeOnUpdateNowFlag(col)
-			case coldef.ConstrOnUpdate:
-				if !evaluator.IsCurrentTimeExpr(v.Evalue) {
+			case ast.ColumnOptionOnUpdate:
+				if !evaluator.IsCurrentTimeExpr(v.Expr) {
 					return nil, nil, errors.Errorf("invalid ON UPDATE for - %s", col.Name)
 				}
 
 				col.Flag |= mysql.OnUpdateNowFlag
 				setOnUpdateNow = true
-			case coldef.ConstrFulltext:
-			// Do nothing.
-			case coldef.ConstrComment:
+			case ast.ColumnOptionFulltext, ast.ColumnOptionComment:
 				// Do nothing.
 			}
 		}
@@ -499,9 +496,9 @@ func columnDefToCol(ctx context.Context, offset int, colDef *coldef.ColumnDef) (
 	return col, constraints, nil
 }
 
-func getDefaultValue(ctx context.Context, c *coldef.ConstraintOpt, tp byte, fsp int) (interface{}, error) {
+func getDefaultValue(ctx context.Context, c *ast.ColumnOption, tp byte, fsp int) (interface{}, error) {
 	if tp == mysql.TypeTimestamp || tp == mysql.TypeDatetime {
-		value, err := evaluator.GetTimeValue(ctx, c.Evalue, tp, fsp)
+		value, err := evaluator.GetTimeValue(ctx, c.Expr, tp, fsp)
 		if err != nil {
 			return nil, errors.Trace(err)
 		}
@@ -518,7 +515,7 @@ func getDefaultValue(ctx context.Context, c *coldef.ConstraintOpt, tp byte, fsp
 
 		return value, nil
 	}
-	v, err := evaluator.Eval(ctx, c.Evalue)
+	v, err := evaluator.Eval(ctx, c.Expr)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}
@@ -580,10 +577,10 @@ func checkDefaultValue(c *column.Col, hasDefaultValue bool) error {
 	return nil
 }
 
-func checkDuplicateColumn(colDefs []*coldef.ColumnDef) error {
+func checkDuplicateColumn(colDefs []*ast.ColumnDef) error {
 	colNames := map[string]bool{}
 	for _, colDef := range colDefs {
-		nameLower := strings.ToLower(colDef.Name)
+		nameLower := colDef.Name.Name.O
 		if colNames[nameLower] {
 			return errors.Errorf("CREATE TABLE: duplicate column %s", colDef.Name)
 		}
@@ -592,15 +589,15 @@ func checkDuplicateColumn(colDefs []*coldef.ColumnDef) error {
 	return nil
 }
 
-func checkConstraintNames(constraints []*coldef.TableConstraint) error {
+func checkConstraintNames(constraints []*ast.Constraint) error {
 	constrNames := map[string]bool{}
 
 	// Check not empty constraint name whether is duplicated.
 	for _, constr := range constraints {
-		if constr.ConstrName != "" {
-			nameLower := strings.ToLower(constr.ConstrName)
+		if constr.Name != "" {
+			nameLower := strings.ToLower(constr.Name)
 			if constrNames[nameLower] {
-				return errors.Errorf("CREATE TABLE: duplicate key %s", constr.ConstrName)
+				return errors.Errorf("CREATE TABLE: duplicate key %s", constr.Name)
 			}
 			constrNames[nameLower] = true
 		}
@@ -608,8 +605,8 @@ func checkConstraintNames(constraints []*coldef.TableConstraint) error {
 
 	// Set empty constraint names.
 	for _, constr := range constraints {
-		if constr.ConstrName == "" && len(constr.Keys) > 0 {
-			colName := constr.Keys[0].ColumnName
+		if constr.Name == "" && len(constr.Keys) > 0 {
+			colName := constr.Keys[0].Column.Name.O
 			constrName := colName
 			i := 2
 			for constrNames[strings.ToLower(constrName)] {
@@ -617,14 +614,14 @@ func checkConstraintNames(constraints []*coldef.TableConstraint) error {
 				constrName = fmt.Sprintf("%s_%d", colName, i)
 				i++
 			}
-			constr.ConstrName = constrName
+			constr.Name = constrName
 			constrNames[constrName] = true
 		}
 	}
 	return nil
 }
 
-func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constraints []*coldef.TableConstraint) (tbInfo *model.TableInfo, err error) {
+func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constraints []*ast.Constraint) (tbInfo *model.TableInfo, err error) {
 	tbInfo = &model.TableInfo{
 		Name: tableName,
 	}
@@ -636,10 +633,10 @@ func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constrai
 		tbInfo.Columns = append(tbInfo.Columns, &v.ColumnInfo)
 	}
 	for _, constr := range constraints {
-		if constr.Tp == coldef.ConstrPrimaryKey {
+		if constr.Tp == ast.ConstraintPrimaryKey {
 			if len(constr.Keys) == 1 {
 				key := constr.Keys[0]
-				col := column.FindCol(cols, key.ColumnName)
+				col := column.FindCol(cols, key.Column.Name.O)
 				if col == nil {
 					return nil, errors.Errorf("No such column: %v", key)
 				}
@@ -656,27 +653,27 @@ func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constrai
 		// 2. add index
 		indexColumns := make([]*model.IndexColumn, 0, len(constr.Keys))
 		for _, key := range constr.Keys {
-			col := column.FindCol(cols, key.ColumnName)
+			col := column.FindCol(cols, key.Column.Name.O)
 			if col == nil {
 				return nil, errors.Errorf("No such column: %v", key)
 			}
 			indexColumns = append(indexColumns, &model.IndexColumn{
-				Name:   model.NewCIStr(key.ColumnName),
+				Name:   key.Column.Name,
 				Offset: col.Offset,
 				Length: key.Length,
 			})
 		}
 		idxInfo := &model.IndexInfo{
-			Name:    model.NewCIStr(constr.ConstrName),
+			Name:    model.NewCIStr(constr.Name),
 			Columns: indexColumns,
 			State:   model.StatePublic,
 		}
 		switch constr.Tp {
-		case coldef.ConstrPrimaryKey:
+		case ast.ConstraintPrimaryKey:
 			idxInfo.Unique = true
 			idxInfo.Primary = true
 			idxInfo.Name = model.NewCIStr(column.PrimaryKeyName)
-		case coldef.ConstrUniq, coldef.ConstrUniqKey, coldef.ConstrUniqIndex:
+		case ast.ConstraintUniq, ast.ConstraintUniqKey, ast.ConstraintUniqIndex:
 			idxInfo.Unique = true
 		}
 		idxInfo.ID, err = d.genGlobalID()
@@ -688,7 +685,7 @@ func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constrai
 	return
 }
 
-func (d *ddl) CreateTable(ctx context.Context, ident table.Ident, colDefs []*coldef.ColumnDef, constraints []*coldef.TableConstraint) (err error) {
+func (d *ddl) CreateTable(ctx context.Context, ident ast.Ident, colDefs []*ast.ColumnDef, constraints []*ast.Constraint) (err error) {
 	is := d.GetInformationSchema()
 	schema, ok := is.SchemaByName(ident.Schema)
 	if !ok {
@@ -728,27 +725,27 @@ func (d *ddl) CreateTable(ctx context.Context, ident table.Ident, colDefs []*col
 	return errors.Trace(err)
 }
 
-func (d *ddl) AlterTable(ctx context.Context, ident table.Ident, specs []*AlterSpecification) (err error) {
+func (d *ddl) AlterTable(ctx context.Context, ident ast.Ident, specs []*ast.AlterTableSpec) (err error) {
 	// now we only allow one schema changes at the same time.
 	if len(specs) != 1 {
 		return errors.New("can't run multi schema changes in one DDL")
 	}
 
 	for _, spec := range specs {
-		switch spec.Action {
-		case AlterAddColumn:
+		switch spec.Tp {
+		case ast.AlterTableAddColumn:
 			err = d.AddColumn(ctx, ident, spec)
-		case AlterDropColumn:
-			err = d.DropColumn(ctx, ident, model.NewCIStr(spec.Name))
-		case AlterDropIndex:
+		case ast.AlterTableDropColumn:
+			err = d.DropColumn(ctx, ident, spec.DropColumn.Name)
+		case ast.AlterTableDropIndex:
 			err = d.DropIndex(ctx, ident, model.NewCIStr(spec.Name))
-		case AlterAddConstr:
+		case ast.AlterTableAddConstraint:
 			constr := spec.Constraint
 			switch spec.Constraint.Tp {
-			case coldef.ConstrKey, coldef.ConstrIndex:
-				err = d.CreateIndex(ctx, ident, false, model.NewCIStr(constr.ConstrName), spec.Constraint.Keys)
-			case coldef.ConstrUniq, coldef.ConstrUniqIndex, coldef.ConstrUniqKey:
-				err = d.CreateIndex(ctx, ident, true, model.NewCIStr(constr.ConstrName), spec.Constraint.Keys)
+			case ast.ConstraintKey, ast.ConstraintIndex:
+				err = d.CreateIndex(ctx, ident, false, model.NewCIStr(constr.Name), spec.Constraint.Keys)
+			case ast.ConstraintUniq, ast.ConstraintUniqIndex, ast.ConstraintUniqKey:
+				err = d.CreateIndex(ctx, ident, true, model.NewCIStr(constr.Name), spec.Constraint.Keys)
 			default:
 				// nothing to do now.
 			}
@@ -764,11 +761,11 @@ func (d *ddl) AlterTable(ctx context.Context, ident table.Ident, specs []*AlterS
 	return nil
 }
 
-func checkColumnConstraint(constraints []*coldef.ConstraintOpt) error {
+func checkColumnConstraint(constraints []*ast.ColumnOption) error {
 	for _, constraint := range constraints {
 		switch constraint.Tp {
-		case coldef.ConstrAutoIncrement, coldef.ConstrForeignKey, coldef.ConstrPrimaryKey, coldef.ConstrUniq, coldef.ConstrUniqKey:
-			return errors.Errorf("unsupported add column constraint - %s", constraint)
+		case ast.ColumnOptionAutoIncrement, ast.ColumnOptionPrimaryKey, ast.ColumnOptionUniq, ast.ColumnOptionUniqKey:
+			return errors.Errorf("unsupported add column constraint - %v", constraint.Tp)
 		}
 	}
 
@@ -776,9 +773,9 @@ func checkColumnConstraint(constraints []*coldef.ConstraintOpt) error {
 }
 
 // AddColumn will add a new column to the table.
-func (d *ddl) AddColumn(ctx context.Context, ti table.Ident, spec *AlterSpecification) error {
+func (d *ddl) AddColumn(ctx context.Context, ti ast.Ident, spec *ast.AlterTableSpec) error {
 	// Check whether the added column constraints are supported.
-	err := checkColumnConstraint(spec.Column.Constraints)
+	err := checkColumnConstraint(spec.Column.Options)
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -795,7 +792,7 @@ func (d *ddl) AddColumn(ctx context.Context, ti table.Ident, spec *AlterSpecific
 	}
 
 	// Check whether added column has existed.
-	colName := spec.Column.Name
+	colName := spec.Column.Name.Name.O
 	col := column.FindCol(t.Cols(), colName)
 	if col != nil {
 		return errors.Errorf("column %s already exists", colName)
@@ -822,7 +819,7 @@ func (d *ddl) AddColumn(ctx context.Context, ti table.Ident, spec *AlterSpecific
 }
 
 // DropColumn will drop a column from the table, now we don't support drop the column with index covered.
-func (d *ddl) DropColumn(ctx context.Context, ti table.Ident, colName model.CIStr) error {
+func (d *ddl) DropColumn(ctx context.Context, ti ast.Ident, colName model.CIStr) error {
 	is := d.infoHandle.Get()
 	schema, ok := is.SchemaByName(ti.Schema)
 	if !ok {
@@ -853,7 +850,7 @@ func (d *ddl) DropColumn(ctx context.Context, ti table.Ident, colName model.CISt
 }
 
 // DropTable will proceed even if some table in the list does not exists.
-func (d *ddl) DropTable(ctx context.Context, ti table.Ident) (err error) {
+func (d *ddl) DropTable(ctx context.Context, ti ast.Ident) (err error) {
 	is := d.GetInformationSchema()
 	schema, ok := is.SchemaByName(ti.Schema)
 	if !ok {
@@ -876,7 +873,7 @@ func (d *ddl) DropTable(ctx context.Context, ti table.Ident) (err error) {
 	return errors.Trace(err)
 }
 
-func (d *ddl) CreateIndex(ctx context.Context, ti table.Ident, unique bool, indexName model.CIStr, idxColNames []*coldef.IndexColName) error {
+func (d *ddl) CreateIndex(ctx context.Context, ti ast.Ident, unique bool, indexName model.CIStr, idxColNames []*ast.IndexColName) error {
 	is := d.infoHandle.Get()
 	schema, ok := is.SchemaByName(ti.Schema)
 	if !ok {
@@ -904,7 +901,7 @@ func (d *ddl) CreateIndex(ctx context.Context, ti table.Ident, unique bool, inde
 	return errors.Trace(err)
 }
 
-func (d *ddl) DropIndex(ctx context.Context, ti table.Ident, indexName model.CIStr) error {
+func (d *ddl) DropIndex(ctx context.Context, ti ast.Ident, indexName model.CIStr) error {
 	is := d.infoHandle.Get()
 	schema, ok := is.SchemaByName(ti.Schema)
 	if !ok {
diff --git a/ddl/ddl_test.go b/ddl/ddl_test.go
index 7c7642803645e..01cbf07dfb603 100644
--- a/ddl/ddl_test.go
+++ b/ddl/ddl_test.go
@@ -19,8 +19,8 @@ import (
 	"github.com/ngaut/log"
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/kv"
-	"github.com/pingcap/tidb/parser/coldef"
 )
 
 func TestT(t *testing.T) {
@@ -31,14 +31,14 @@ var _ = Suite(&testSuite{})
 
 type testSuite struct {
 	store       kv.Storage
-	charsetInfo *coldef.CharsetOpt
+	charsetInfo *ast.CharsetOpt
 }
 
 func (ts *testSuite) SetUpSuite(c *C) {
 	store, err := tidb.NewStore(tidb.EngineGoLevelDBMemory)
 	c.Assert(err, IsNil)
 	ts.store = store
-	ts.charsetInfo = &coldef.CharsetOpt{
+	ts.charsetInfo = &ast.CharsetOpt{
 		Chs: "utf8",
 		Col: "utf8_bin",
 	}
diff --git a/ddl/ddl_worker_test.go b/ddl/ddl_worker_test.go
index 4c69fe2469c6c..c96621abc7bfd 100644
--- a/ddl/ddl_worker_test.go
+++ b/ddl/ddl_worker_test.go
@@ -19,11 +19,11 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/store/localstore"
 	"github.com/pingcap/tidb/store/localstore/goleveldb"
 	"github.com/pingcap/tidb/terror"
@@ -251,7 +251,7 @@ func (s *testDDLSuite) TestIndexError(c *C) {
 		SchemaID: dbInfo.ID,
 		TableID:  tblInfo.ID,
 		Type:     model.ActionAddIndex,
-		Args:     []interface{}{false, model.NewCIStr("t"), []*coldef.IndexColName{{ColumnName: "c", Length: 256}}},
+		Args:     []interface{}{false, model.NewCIStr("t"), []*ast.IndexColName{{Column: &ast.ColumnName{Name: model.NewCIStr("c")}, Length: 256}}},
 	}
 	err = d.startDDLJob(ctx, job)
 	c.Assert(err, NotNil)
@@ -261,7 +261,7 @@ func (s *testDDLSuite) TestIndexError(c *C) {
 		SchemaID: dbInfo.ID,
 		TableID:  tblInfo.ID,
 		Type:     model.ActionAddIndex,
-		Args:     []interface{}{false, model.NewCIStr("c1_index"), []*coldef.IndexColName{{ColumnName: "c", Length: 256}}},
+		Args:     []interface{}{false, model.NewCIStr("c1_index"), []*ast.IndexColName{{Column: &ast.ColumnName{Name: model.NewCIStr("c")}, Length: 256}}},
 	}
 	err = d.startDDLJob(ctx, job)
 	c.Assert(err, NotNil)
@@ -273,7 +273,7 @@ func (s *testDDLSuite) TestIndexError(c *C) {
 		SchemaID: dbInfo.ID,
 		TableID:  tblInfo.ID,
 		Type:     model.ActionAddIndex,
-		Args:     []interface{}{false, model.NewCIStr("c1_index"), []*coldef.IndexColName{{ColumnName: "c1", Length: 256}}},
+		Args:     []interface{}{false, model.NewCIStr("c1_index"), []*ast.IndexColName{{Column: &ast.ColumnName{Name: model.NewCIStr("c1")}, Length: 256}}},
 	}
 	err = d.startDDLJob(ctx, job)
 	c.Assert(err, NotNil)
@@ -349,7 +349,7 @@ func (s *testDDLSuite) TestColumnError(c *C) {
 	c.Assert(err, IsNil)
 
 	col.FieldType = *types.NewFieldType(mysql.TypeLong)
-	pos := &ColumnPosition{Type: ColumnPositionAfter, RelativeColumn: "c5"}
+	pos := &ast.ColumnPosition{Tp: ast.ColumnPositionAfter, RelativeColumn: &ast.ColumnName{Name: model.NewCIStr("c5")}}
 
 	job = &model.Job{
 		SchemaID: dbInfo.ID,
diff --git a/ddl/index.go b/ddl/index.go
index bd62948f9455c..d4f5fc49902f3 100644
--- a/ddl/index.go
+++ b/ddl/index.go
@@ -16,11 +16,11 @@ package ddl
 import (
 	"github.com/juju/errors"
 	"github.com/ngaut/log"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/meta"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/terror"
@@ -28,13 +28,13 @@ import (
 	"github.com/pingcap/tidb/util/types"
 )
 
-func buildIndexInfo(tblInfo *model.TableInfo, unique bool, indexName model.CIStr, indexID int64, idxColNames []*coldef.IndexColName) (*model.IndexInfo, error) {
+func buildIndexInfo(tblInfo *model.TableInfo, unique bool, indexName model.CIStr, indexID int64, idxColNames []*ast.IndexColName) (*model.IndexInfo, error) {
 	// build offsets
 	idxColumns := make([]*model.IndexColumn, 0, len(idxColNames))
 	for _, ic := range idxColNames {
-		col := findCol(tblInfo.Columns, ic.ColumnName)
+		col := findCol(tblInfo.Columns, ic.Column.Name.O)
 		if col == nil {
-			return nil, errors.Errorf("CREATE INDEX: column does not exist: %s", ic.ColumnName)
+			return nil, errors.Errorf("CREATE INDEX: column does not exist: %s", ic.Column.Name.O)
 		}
 
 		idxColumns = append(idxColumns, &model.IndexColumn{
@@ -98,7 +98,7 @@ func (d *ddl) onCreateIndex(t *meta.Meta, job *model.Job) error {
 		unique      bool
 		indexName   model.CIStr
 		indexID     int64
-		idxColNames []*coldef.IndexColName
+		idxColNames []*ast.IndexColName
 	)
 
 	err = job.DecodeArgs(&unique, &indexName, &indexID, &idxColNames)
diff --git a/ddl/index_test.go b/ddl/index_test.go
index 43399e7df845f..e5d31c0544122 100644
--- a/ddl/index_test.go
+++ b/ddl/index_test.go
@@ -18,11 +18,11 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/kv"
 	"github.com/pingcap/tidb/model"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/util/mock"
@@ -66,7 +66,7 @@ func testCreateIndex(c *C, ctx context.Context, d *ddl, dbInfo *model.DBInfo, tb
 		SchemaID: dbInfo.ID,
 		TableID:  tblInfo.ID,
 		Type:     model.ActionAddIndex,
-		Args:     []interface{}{unique, model.NewCIStr(indexName), id, []*coldef.IndexColName{{ColumnName: colName, Length: 256}}},
+		Args:     []interface{}{unique, model.NewCIStr(indexName), id, []*ast.IndexColName{{Column: &ast.ColumnName{Name: model.NewCIStr(colName)}, Length: 256}}},
 	}
 
 	err = d.startDDLJob(ctx, job)
diff --git a/domain/domain_test.go b/domain/domain_test.go
index f31e556479910..f521d1d757aba 100644
--- a/domain/domain_test.go
+++ b/domain/domain_test.go
@@ -19,8 +19,8 @@ import (
 	"time"
 
 	. "github.com/pingcap/check"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/model"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/store/localstore"
 	"github.com/pingcap/tidb/store/localstore/goleveldb"
@@ -49,7 +49,7 @@ func (*testSuite) TestT(c *C) {
 	store = dom.Store()
 	dd := dom.DDL()
 	c.Assert(dd, NotNil)
-	cs := &coldef.CharsetOpt{
+	cs := &ast.CharsetOpt{
 		Chs: "utf8",
 		Col: "utf8_bin",
 	}
diff --git a/driver.go b/driver.go
index 9073bd0c3cfd4..f8b95421ac623 100644
--- a/driver.go
+++ b/driver.go
@@ -31,7 +31,6 @@ import (
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/model"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/sessionctx"
 	"github.com/pingcap/tidb/terror"
 	"github.com/pingcap/tidb/util/types"
@@ -203,7 +202,7 @@ func (d *sqlDriver) Open(dsn string) (driver.Conn, error) {
 
 	DBName := model.NewCIStr(params.dbName)
 	domain := sessionctx.GetDomain(s)
-	cs := &coldef.CharsetOpt{
+	cs := &ast.CharsetOpt{
 		Chs: "utf8",
 		Col: "utf8_bin",
 	}
diff --git a/executor/executor_ddl.go b/executor/executor_ddl.go
index b43867e2f2429..328c60ae0ed1a 100644
--- a/executor/executor_ddl.go
+++ b/executor/executor_ddl.go
@@ -19,14 +19,11 @@ import (
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/context"
-	"github.com/pingcap/tidb/ddl"
 	"github.com/pingcap/tidb/infoschema"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/privilege"
 	"github.com/pingcap/tidb/sessionctx"
-	"github.com/pingcap/tidb/table"
 	"github.com/pingcap/tidb/terror"
 )
 
@@ -88,9 +85,9 @@ func (e *DDLExec) executeTruncateTable(s *ast.TruncateTableStmt) error {
 }
 
 func (e *DDLExec) executeCreateDatabase(s *ast.CreateDatabaseStmt) error {
-	var opt *coldef.CharsetOpt
+	var opt *ast.CharsetOpt
 	if len(s.Options) != 0 {
-		opt = &coldef.CharsetOpt{}
+		opt = &ast.CharsetOpt{}
 		for _, val := range s.Options {
 			switch val.Tp {
 			case ast.DatabaseOptionCharset:
@@ -110,26 +107,8 @@ func (e *DDLExec) executeCreateDatabase(s *ast.CreateDatabaseStmt) error {
 }
 
 func (e *DDLExec) executeCreateTable(s *ast.CreateTableStmt) error {
-	ident := table.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
-
-	var coldefs []*coldef.ColumnDef
-	for _, val := range s.Cols {
-		coldef, err := convertColumnDef(val)
-		if err != nil {
-			return errors.Trace(err)
-		}
-		coldefs = append(coldefs, coldef)
-	}
-	var constrs []*coldef.TableConstraint
-	for _, val := range s.Constraints {
-		constr, err := convertConstraint(val)
-		if err != nil {
-			return errors.Trace(err)
-		}
-		constrs = append(constrs, constr)
-	}
-
-	err := sessionctx.GetDomain(e.ctx).DDL().CreateTable(e.ctx, ident, coldefs, constrs)
+	ident := ast.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
+	err := sessionctx.GetDomain(e.ctx).DDL().CreateTable(e.ctx, ident, s.Cols, s.Constraints)
 	if terror.ErrorEqual(err, infoschema.TableExists) {
 		if s.IfNotExists {
 			return nil
@@ -139,105 +118,9 @@ func (e *DDLExec) executeCreateTable(s *ast.CreateTableStmt) error {
 	return errors.Trace(err)
 }
 
-func convertColumnDef(v *ast.ColumnDef) (*coldef.ColumnDef, error) {
-	oldColDef := &coldef.ColumnDef{
-		Name: v.Name.Name.O,
-		Tp:   v.Tp,
-	}
-	for _, val := range v.Options {
-		oldOpt, err := convertColumnOption(val)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		oldColDef.Constraints = append(oldColDef.Constraints, oldOpt)
-	}
-	return oldColDef, nil
-}
-
-func convertColumnOption(v *ast.ColumnOption) (*coldef.ConstraintOpt, error) {
-	oldColumnOpt := &coldef.ConstraintOpt{}
-	switch v.Tp {
-	case ast.ColumnOptionAutoIncrement:
-		oldColumnOpt.Tp = coldef.ConstrAutoIncrement
-	case ast.ColumnOptionComment:
-		oldColumnOpt.Tp = coldef.ConstrComment
-	case ast.ColumnOptionDefaultValue:
-		oldColumnOpt.Tp = coldef.ConstrDefaultValue
-	case ast.ColumnOptionIndex:
-		oldColumnOpt.Tp = coldef.ConstrIndex
-	case ast.ColumnOptionKey:
-		oldColumnOpt.Tp = coldef.ConstrKey
-	case ast.ColumnOptionFulltext:
-		oldColumnOpt.Tp = coldef.ConstrFulltext
-	case ast.ColumnOptionNotNull:
-		oldColumnOpt.Tp = coldef.ConstrNotNull
-	case ast.ColumnOptionNoOption:
-		oldColumnOpt.Tp = coldef.ConstrNoConstr
-	case ast.ColumnOptionOnUpdate:
-		oldColumnOpt.Tp = coldef.ConstrOnUpdate
-	case ast.ColumnOptionPrimaryKey:
-		oldColumnOpt.Tp = coldef.ConstrPrimaryKey
-	case ast.ColumnOptionNull:
-		oldColumnOpt.Tp = coldef.ConstrNull
-	case ast.ColumnOptionUniq:
-		oldColumnOpt.Tp = coldef.ConstrUniq
-	case ast.ColumnOptionUniqIndex:
-		oldColumnOpt.Tp = coldef.ConstrUniqIndex
-	case ast.ColumnOptionUniqKey:
-		oldColumnOpt.Tp = coldef.ConstrUniqKey
-	}
-	oldColumnOpt.Evalue = v.Expr
-	return oldColumnOpt, nil
-}
-
-func convertConstraint(v *ast.Constraint) (*coldef.TableConstraint, error) {
-	oldConstraint := &coldef.TableConstraint{ConstrName: v.Name}
-	switch v.Tp {
-	case ast.ConstraintNoConstraint:
-		oldConstraint.Tp = coldef.ConstrNoConstr
-	case ast.ConstraintPrimaryKey:
-		oldConstraint.Tp = coldef.ConstrPrimaryKey
-	case ast.ConstraintKey:
-		oldConstraint.Tp = coldef.ConstrKey
-	case ast.ConstraintIndex:
-		oldConstraint.Tp = coldef.ConstrIndex
-	case ast.ConstraintUniq:
-		oldConstraint.Tp = coldef.ConstrUniq
-	case ast.ConstraintUniqKey:
-		oldConstraint.Tp = coldef.ConstrUniqKey
-	case ast.ConstraintUniqIndex:
-		oldConstraint.Tp = coldef.ConstrUniqIndex
-	case ast.ConstraintForeignKey:
-		oldConstraint.Tp = coldef.ConstrForeignKey
-	case ast.ConstraintFulltext:
-		oldConstraint.Tp = coldef.ConstrFulltext
-	}
-	oldConstraint.Keys = convertIndexColNames(v.Keys)
-	if v.Refer != nil {
-		oldConstraint.Refer = &coldef.ReferenceDef{
-			TableIdent:    table.Ident{Schema: v.Refer.Table.Schema, Name: v.Refer.Table.Name},
-			IndexColNames: convertIndexColNames(v.Refer.IndexColNames),
-		}
-	}
-	return oldConstraint, nil
-}
-
-func convertIndexColNames(v []*ast.IndexColName) (out []*coldef.IndexColName) {
-	for _, val := range v {
-		oldIndexColKey := &coldef.IndexColName{
-			ColumnName: val.Column.Name.O,
-			Length:     val.Length,
-		}
-		out = append(out, oldIndexColKey)
-	}
-	return
-}
-
 func (e *DDLExec) executeCreateIndex(s *ast.CreateIndexStmt) error {
-	ident := table.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
-
-	colNames := convertIndexColNames(s.IndexColNames)
-	err := sessionctx.GetDomain(e.ctx).DDL().CreateIndex(e.ctx, ident, s.Unique, model.NewCIStr(s.IndexName), colNames)
+	ident := ast.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
+	err := sessionctx.GetDomain(e.ctx).DDL().CreateIndex(e.ctx, ident, s.Unique, model.NewCIStr(s.IndexName), s.IndexColNames)
 	return errors.Trace(err)
 }
 
@@ -256,7 +139,7 @@ func (e *DDLExec) executeDropDatabase(s *ast.DropDatabaseStmt) error {
 func (e *DDLExec) executeDropTable(s *ast.DropTableStmt) error {
 	var notExistTables []string
 	for _, tn := range s.Tables {
-		fullti := table.Ident{Schema: tn.Schema, Name: tn.Name}
+		fullti := ast.Ident{Schema: tn.Schema, Name: tn.Name}
 		schema, ok := e.is.SchemaByName(tn.Schema)
 		if !ok {
 			// TODO: we should return special error for table not exist, checking "not exist" is not enough,
@@ -295,7 +178,7 @@ func (e *DDLExec) executeDropTable(s *ast.DropTableStmt) error {
 }
 
 func (e *DDLExec) executeDropIndex(s *ast.DropIndexStmt) error {
-	ti := table.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
+	ti := ast.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
 	err := sessionctx.GetDomain(e.ctx).DDL().DropIndex(e.ctx, ti, model.NewCIStr(s.IndexName))
 	if (infoschema.DatabaseNotExists.Equal(err) || infoschema.TableNotExists.Equal(err)) && s.IfExists {
 		err = nil
@@ -304,112 +187,11 @@ func (e *DDLExec) executeDropIndex(s *ast.DropIndexStmt) error {
 }
 
 func (e *DDLExec) executeAlterTable(s *ast.AlterTableStmt) error {
-	ti := table.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
-	var specs []*ddl.AlterSpecification
-	for _, v := range s.Specs {
-		spec, err := convertAlterTableSpec(v)
-		if err != nil {
-			return errors.Trace(err)
-		}
-		specs = append(specs, spec)
-	}
-	err := sessionctx.GetDomain(e.ctx).DDL().AlterTable(e.ctx, ti, specs)
+	ti := ast.Ident{Schema: s.Table.Schema, Name: s.Table.Name}
+	err := sessionctx.GetDomain(e.ctx).DDL().AlterTable(e.ctx, ti, s.Specs)
 	return errors.Trace(err)
 }
 
-func convertAlterTableSpec(v *ast.AlterTableSpec) (*ddl.AlterSpecification, error) {
-	oldAlterSpec := &ddl.AlterSpecification{
-		Name: v.Name,
-	}
-	switch v.Tp {
-	case ast.AlterTableAddConstraint:
-		oldAlterSpec.Action = ddl.AlterAddConstr
-	case ast.AlterTableAddColumn:
-		oldAlterSpec.Action = ddl.AlterAddColumn
-	case ast.AlterTableDropColumn:
-		oldAlterSpec.Action = ddl.AlterDropColumn
-	case ast.AlterTableDropForeignKey:
-		oldAlterSpec.Action = ddl.AlterDropForeignKey
-	case ast.AlterTableDropIndex:
-		oldAlterSpec.Action = ddl.AlterDropIndex
-	case ast.AlterTableDropPrimaryKey:
-		oldAlterSpec.Action = ddl.AlterDropPrimaryKey
-	case ast.AlterTableOption:
-		oldAlterSpec.Action = ddl.AlterTableOpt
-	}
-	if v.Column != nil {
-		oldColDef, err := convertColumnDef(v.Column)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		oldAlterSpec.Column = oldColDef
-	}
-	if v.Position != nil {
-		oldAlterSpec.Position = &ddl.ColumnPosition{}
-		switch v.Position.Tp {
-		case ast.ColumnPositionNone:
-			oldAlterSpec.Position.Type = ddl.ColumnPositionNone
-		case ast.ColumnPositionFirst:
-			oldAlterSpec.Position.Type = ddl.ColumnPositionFirst
-		case ast.ColumnPositionAfter:
-			oldAlterSpec.Position.Type = ddl.ColumnPositionAfter
-		}
-		if v.Position.RelativeColumn != nil {
-			oldAlterSpec.Position.RelativeColumn = joinColumnName(v.Position.RelativeColumn)
-		}
-	}
-	if v.DropColumn != nil {
-		oldAlterSpec.Name = joinColumnName(v.DropColumn)
-	}
-	if v.Constraint != nil {
-		oldConstraint, err := convertConstraint(v.Constraint)
-		if err != nil {
-			return nil, errors.Trace(err)
-		}
-		oldAlterSpec.Constraint = oldConstraint
-	}
-	for _, val := range v.Options {
-		oldOpt := &coldef.TableOpt{
-			StrValue:  val.StrValue,
-			UintValue: val.UintValue,
-		}
-		switch val.Tp {
-		case ast.TableOptionNone:
-			oldOpt.Tp = coldef.TblOptNone
-		case ast.TableOptionEngine:
-			oldOpt.Tp = coldef.TblOptEngine
-		case ast.TableOptionCharset:
-			oldOpt.Tp = coldef.TblOptCharset
-		case ast.TableOptionCollate:
-			oldOpt.Tp = coldef.TblOptCollate
-		case ast.TableOptionAutoIncrement:
-			oldOpt.Tp = coldef.TblOptAutoIncrement
-		case ast.TableOptionComment:
-			oldOpt.Tp = coldef.TblOptComment
-		case ast.TableOptionAvgRowLength:
-			oldOpt.Tp = coldef.TblOptAvgRowLength
-		case ast.TableOptionCheckSum:
-			oldOpt.Tp = coldef.TblOptCheckSum
-		case ast.TableOptionCompression:
-			oldOpt.Tp = coldef.TblOptCompression
-		case ast.TableOptionConnection:
-			oldOpt.Tp = coldef.TblOptConnection
-		case ast.TableOptionPassword:
-			oldOpt.Tp = coldef.TblOptPassword
-		case ast.TableOptionKeyBlockSize:
-			oldOpt.Tp = coldef.TblOptKeyBlockSize
-		case ast.TableOptionMaxRows:
-			oldOpt.Tp = coldef.TblOptMaxRows
-		case ast.TableOptionMinRows:
-			oldOpt.Tp = coldef.TblOptMinRows
-		case ast.TableOptionDelayKeyWrite:
-			oldOpt.Tp = coldef.TblOptDelayKeyWrite
-		}
-		oldAlterSpec.TableOpts = append(oldAlterSpec.TableOpts, oldOpt)
-	}
-	return oldAlterSpec, nil
-}
-
 func joinColumnName(columnName *ast.ColumnName) string {
 	var originStrs []string
 	if columnName.Schema.O != "" {
diff --git a/parser/coldef/col_def.go b/parser/coldef/col_def.go
deleted file mode 100644
index ad1a9618fda9d..0000000000000
--- a/parser/coldef/col_def.go
+++ /dev/null
@@ -1,79 +0,0 @@
-// Copyright 2015 PingCAP, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package coldef
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/pingcap/tidb/table"
-	"github.com/pingcap/tidb/util/types"
-)
-
-// ReferenceDef is used for parsing foreign key reference option from SQL.
-// See: http://dev.mysql.com/doc/refman/5.7/en/create-table-foreign-keys.html
-type ReferenceDef struct {
-	TableIdent    table.Ident
-	IndexColNames []*IndexColName
-}
-
-// String implements fmt.Stringer interface.
-func (rd *ReferenceDef) String() string {
-	cns := make([]string, 0, len(rd.IndexColNames))
-	for _, icn := range rd.IndexColNames {
-		cns = append(cns, icn.String())
-	}
-	return fmt.Sprintf("REFERENCES %s (%s)", rd.TableIdent, strings.Join(cns, ", "))
-}
-
-// Clone clones a new ReferenceDef from old ReferenceDef.
-func (rd *ReferenceDef) Clone() *ReferenceDef {
-	cnames := make([]*IndexColName, 0, len(rd.IndexColNames))
-	for _, idxColName := range rd.IndexColNames {
-		t := *idxColName
-		cnames = append(cnames, &t)
-	}
-	return &ReferenceDef{TableIdent: rd.TableIdent, IndexColNames: cnames}
-}
-
-// IndexColName is used for parsing index column name from SQL.
-type IndexColName struct {
-	ColumnName string
-	Length     int
-}
-
-// String implements fmt.Stringer interface.
-func (icn *IndexColName) String() string {
-	if icn.Length >= 0 {
-		return fmt.Sprintf("%s(%d)", icn.ColumnName, icn.Length)
-	}
-	return icn.ColumnName
-}
-
-// ColumnDef is used for parsing column definition from SQL.
-type ColumnDef struct {
-	Name        string
-	Tp          *types.FieldType
-	Constraints []*ConstraintOpt
-}
-
-// String implements fmt.Stringer interface.
-func (c *ColumnDef) String() string {
-	ans := []string{c.Name}
-
-	for _, x := range c.Constraints {
-		ans = append(ans, x.String())
-	}
-	return strings.Join(ans, " ")
-}
diff --git a/parser/coldef/opt.go b/parser/coldef/opt.go
deleted file mode 100644
index c35cda20ddc53..0000000000000
--- a/parser/coldef/opt.go
+++ /dev/null
@@ -1,281 +0,0 @@
-// Copyright 2015 PingCAP, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package coldef
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/pingcap/tidb/ast"
-	"github.com/pingcap/tidb/mysql"
-)
-
-// FloatOpt is used for parsing floating-point type option from SQL.
-// TODO: add reference doc.
-type FloatOpt struct {
-	Flen    int
-	Decimal int
-}
-
-// CharsetOpt is used for parsing charset option from SQL.
-type CharsetOpt struct {
-	Chs string
-	Col string
-}
-
-// String implements fmt.Stringer interface.
-func (o *CharsetOpt) String() string {
-	var ss []string
-	if o.Chs != "" {
-		ss = append(ss, "CHARACTER SET = "+o.Chs)
-	}
-	if o.Col != "" {
-		ss = append(ss, "COLLATE = "+o.Col)
-	}
-	return strings.Join(ss, " ")
-}
-
-// ConstraintOpt is used for parsing column constraint info from SQL.
-type ConstraintOpt struct {
-	Tp     int
-	Bvalue bool
-	Evalue ast.ExprNode
-}
-
-// String implements fmt.Stringer interface.
-func (c *ConstraintOpt) String() string {
-	switch c.Tp {
-	case ConstrNotNull:
-		return "NOT NULL"
-	case ConstrNull:
-		return "NULL"
-	case ConstrAutoIncrement:
-		return "AUTO_INCREMENT"
-	case ConstrPrimaryKey:
-		return "PRIMARY KEY"
-	case ConstrUniq:
-		return "UNIQUE"
-	case ConstrUniqKey:
-		return "UNIQUE KEY"
-	case ConstrDefaultValue:
-		return "DEFAULT " + ast.ToString(c.Evalue)
-	case ConstrOnUpdate:
-		return "ON UPDATE " + ast.ToString(c.Evalue)
-	default:
-		return ""
-	}
-}
-
-// DB Options.
-const (
-	DBOptNone = iota
-	DBOptCharset
-	DBOptCollate
-)
-
-// DatabaseOpt is used for parsing database option from SQL.
-type DatabaseOpt struct {
-	Tp    int
-	Value string
-}
-
-// Constraints.
-const (
-	ConstrNoConstr = iota
-	ConstrPrimaryKey
-	ConstrForeignKey
-	ConstrNotNull
-	ConstrAutoIncrement
-	ConstrDefaultValue
-	ConstrUniq
-	ConstrIndex
-	ConstrUniqIndex
-	ConstrKey
-	ConstrUniqKey
-	ConstrNull
-	ConstrOnUpdate
-	ConstrFulltext
-	ConstrComment
-)
-
-// LockType is select lock type.
-type LockType int
-
-// Select Lock Type.
-const (
-	SelectLockNone LockType = iota
-	SelectLockForUpdate
-	SelectLockInShareMode
-)
-
-// Table Options.
-const (
-	TblOptNone = iota
-	TblOptEngine
-	TblOptCharset
-	TblOptCollate
-	TblOptAutoIncrement
-	TblOptComment
-	TblOptAvgRowLength
-	TblOptCheckSum
-	TblOptCompression
-	TblOptConnection
-	TblOptPassword
-	TblOptKeyBlockSize
-	TblOptMaxRows
-	TblOptMinRows
-	TblOptDelayKeyWrite
-)
-
-// TableOpt is used for parsing table option from SQL.
-type TableOpt struct {
-	Tp        int
-	StrValue  string
-	UintValue uint64
-}
-
-// TableOption is the collection of table options.
-// TODO: rename TableOpt or TableOption.
-type TableOption struct {
-	Engine        string
-	Charset       string
-	Collate       string
-	AutoIncrement uint64 // TODO: apply this value to autoid.Allocator.
-}
-
-// String implements fmt.Stringer interface.
-func (o *TableOption) String() string {
-	strs := []string{}
-	if o.Engine != "" {
-		x := fmt.Sprintf("ENGINE=%s", o.Engine)
-		strs = append(strs, x)
-	}
-	if o.Charset != "" {
-		x := fmt.Sprintf("CHARSET=%s", o.Charset)
-		strs = append(strs, x)
-	}
-	if o.Collate != "" {
-		x := fmt.Sprintf("COLLATE=%s", o.Collate)
-		strs = append(strs, x)
-	}
-
-	return strings.Join(strs, " ")
-}
-
-// TableConstraint is constraint for table definition.
-type TableConstraint struct {
-	Tp         int
-	ConstrName string
-
-	// Used for PRIMARY KEY, UNIQUE, ......
-	Keys []*IndexColName
-
-	// Used for foreign key.
-	Refer *ReferenceDef
-}
-
-// Clone clones a new TableConstraint from old TableConstraint.
-func (tc *TableConstraint) Clone() *TableConstraint {
-	keys := make([]*IndexColName, 0, len(tc.Keys))
-	for _, k := range tc.Keys {
-		keys = append(keys, k)
-	}
-	ntc := &TableConstraint{
-		Tp:         tc.Tp,
-		ConstrName: tc.ConstrName,
-		Keys:       keys,
-	}
-	if tc.Refer != nil {
-		ntc.Refer = tc.Refer.Clone()
-	}
-	return ntc
-}
-
-// String implements fmt.Stringer interface.
-func (tc *TableConstraint) String() string {
-	tokens := []string{}
-	if tc.Tp == ConstrPrimaryKey {
-		tokens = append(tokens, "PRIMARY KEY")
-	} else {
-		if tc.Tp == ConstrKey {
-			tokens = append(tokens, "KEY")
-		} else if tc.Tp == ConstrIndex {
-			tokens = append(tokens, "INDEX")
-		} else if tc.Tp == ConstrUniq {
-			tokens = append(tokens, "UNIQUE")
-		} else if tc.Tp == ConstrUniqKey {
-			tokens = append(tokens, "UNIQUE KEY")
-		} else if tc.Tp == ConstrUniqIndex {
-			tokens = append(tokens, "UNIQUE INDEX")
-		} else if tc.Tp == ConstrForeignKey {
-			tokens = append(tokens, "FOREIGN KEY")
-		}
-		tokens = append(tokens, tc.ConstrName)
-	}
-	keysStr := make([]string, 0, len(tc.Keys))
-	for _, v := range tc.Keys {
-		keysStr = append(keysStr, v.String())
-	}
-	tokens = append(tokens, fmt.Sprintf("(%s)", strings.Join(keysStr, ", ")))
-	if tc.Refer != nil {
-		tokens = append(tokens, tc.Refer.String())
-	}
-	return strings.Join(tokens, " ")
-}
-
-// AuthOption is used for parsing create user statement.
-// TODO: support auth_plugin
-type AuthOption struct {
-	// AuthString/HashString can be empty, so we need to decide which one to use.
-	ByAuthString bool
-	AuthString   string
-	HashString   string
-}
-
-// UserSpecification is used for parsing create user statement.
-type UserSpecification struct {
-	User    string
-	AuthOpt *AuthOption
-}
-
-// PrivElem is the privilege type and optional column list.
-type PrivElem struct {
-	Priv mysql.PrivilegeType
-	Cols []string
-}
-
-const (
-	// ObjectTypeNone is for empty object type.
-	ObjectTypeNone = iota
-	// ObjectTypeTable means the following object is a table.
-	ObjectTypeTable
-)
-
-const (
-	// GrantLevelNone is the dummy const for default value.
-	GrantLevelNone = iota
-	// GrantLevelGlobal means the privileges are administrative or apply to all databases on a given server.
-	GrantLevelGlobal
-	// GrantLevelDB means the privileges apply to all objects in a given database.
-	GrantLevelDB
-	// GrantLevelTable means the privileges apply to all columns in a given table.
-	GrantLevelTable
-)
-
-// GrantLevel is used for store the privilege scope.
-type GrantLevel struct {
-	Level     int
-	DBName    string
-	TableName string
-}
diff --git a/parser/parser.go b/parser/parser.go
index 804f66ed289b9..c7b46bf1a1aa6 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -734,8 +734,8 @@ var (
 		57372: 354, // by (3x)
 		57673: 355, // ByItem (3x)
 		57677: 356, // ColumnDef (3x)
-		57691: 357, // Constraint (3x)
-		57393: 358, // constraint (3x)
+		57393: 357, // constraint (3x)
+		57691: 358, // Constraint (3x)
 		57693: 359, // ConstraintKeywordOpt (3x)
 		57715: 360, // DeleteFromStmt (3x)
 		57740: 361, // FieldOpt (3x)
@@ -1302,8 +1302,8 @@ var (
 		"by",
 		"ByItem",
 		"ColumnDef",
-		"Constraint",
 		"constraint",
+		"Constraint",
 		"ConstraintKeywordOpt",
 		"DeleteFromStmt",
 		"FieldOpt",
@@ -2214,7 +2214,7 @@ var (
 		698: {473, 1},
 		699: {522, 1},
 		700: {522, 3},
-		701: {357, 2},
+		701: {358, 2},
 		702: {438, 1},
 		703: {438, 1},
 		704: {438, 4},
@@ -5315,7 +5315,7 @@ var (
 		{673, 673, 673, 673, 6: 673, 9: 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 673, 123: 673},
 		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 198: 1043, 926, 925, 295: 2047},
 		{125: 2048},
-		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 195: 834, 834, 2055, 1075, 926, 925, 234: 2050, 236: 834, 238: 834, 255: 834, 257: 834, 356: 2053, 2054, 2049, 2052, 438: 2056, 525: 2051},
+		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 195: 834, 834, 2055, 1075, 926, 925, 234: 2050, 236: 834, 238: 834, 255: 834, 257: 834, 356: 2053, 2049, 2054, 2052, 438: 2056, 525: 2051},
 		// 1195
 		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 195: 833, 833, 198: 2309, 926, 925, 236: 833, 238: 833, 255: 833, 257: 833, 437: 2308},
 		{25: 2219, 27: 2216, 2215, 39: 2218, 55: 2198, 2192, 2191, 67: 2206, 72: 2212, 2217, 145: 2205, 189: 2200, 253: 87, 258: 2193, 2189, 261: 87, 263: 2190, 2208, 2197, 2204, 2175, 2176, 2195, 2177, 2188, 2210, 2214, 2209, 2187, 2213, 2194, 279: 2196, 2186, 2178, 2207, 2185, 2211, 2180, 2179, 2201, 453: 2184, 2202, 466: 2174, 478: 2182, 2183, 486: 2181, 492: 2199, 2172, 523: 2173, 529: 2203, 532: 2171},
@@ -5398,7 +5398,7 @@ var (
 		{7: 2115, 2077},
 		{4: 800, 800, 7: 800, 800},
 		{2123, 2124, 4: 132, 132, 760, 9: 2128, 2125, 2127, 2129, 2126, 2133, 2121, 2130, 2131, 2132, 128: 2120, 142: 760, 202: 760, 324: 2122, 341: 2135, 370: 2134, 2119},
-		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 195: 834, 834, 2055, 1075, 926, 925, 234: 2050, 236: 834, 238: 834, 255: 834, 257: 834, 356: 2053, 2054, 2049, 2052, 438: 2118},
+		{927, 976, 928, 945, 6: 934, 9: 950, 977, 979, 980, 978, 991, 942, 981, 982, 983, 941, 957, 959, 951, 944, 999, 968, 935, 938, 937, 1009, 989, 1018, 992, 1023, 1025, 1027, 949, 986, 1032, 961, 965, 966, 970, 1002, 930, 936, 939, 940, 974, 1028, 953, 955, 956, 964, 973, 931, 933, 932, 975, 994, 943, 946, 958, 988, 998, 947, 969, 984, 996, 993, 997, 954, 960, 962, 963, 990, 995, 967, 1000, 1001, 971, 929, 1033, 1003, 1004, 1005, 1006, 1008, 1007, 1010, 1011, 1012, 1013, 1014, 1015, 987, 1016, 1017, 924, 1019, 1020, 1021, 1022, 1024, 948, 1026, 1029, 1030, 952, 1031, 985, 972, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 195: 834, 834, 2055, 1075, 926, 925, 234: 2050, 236: 834, 238: 834, 255: 834, 257: 834, 356: 2053, 2049, 2054, 2052, 438: 2118},
 		{7: 148, 148},
 		// 1265
 		{4: 764, 764},
@@ -5661,7 +5661,7 @@ var (
 		// 1480
 		{4: 851, 851, 8: 2358},
 		{4: 850, 850, 8: 850},
-		{841, 841, 841, 841, 6: 841, 9: 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 195: 834, 834, 236: 834, 238: 834, 255: 834, 257: 834, 357: 2352, 2049, 2052, 384: 2345, 2351},
+		{841, 841, 841, 841, 6: 841, 9: 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 195: 834, 834, 236: 834, 238: 834, 255: 834, 257: 834, 357: 2049, 2352, 2052, 384: 2345, 2351},
 		{841, 841, 841, 841, 6: 841, 9: 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 841, 195: 2340, 236: 2343, 238: 2344, 255: 2342, 384: 2345, 2339, 488: 2341},
 		{4: 836, 836, 8: 836},
 		// 1485
diff --git a/privilege/privileges/privileges.go b/privilege/privileges/privileges.go
index 05b7aa4210f81..7ff6588062754 100644
--- a/privilege/privileges/privileges.go
+++ b/privilege/privileges/privileges.go
@@ -18,10 +18,10 @@ import (
 	"strings"
 
 	"github.com/juju/errors"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/parser/coldef"
 	"github.com/pingcap/tidb/privilege"
 	"github.com/pingcap/tidb/sessionctx/variable"
 	"github.com/pingcap/tidb/util/sqlexec"
@@ -31,7 +31,7 @@ import (
 var _ privilege.Checker = (*UserPrivileges)(nil)
 
 type privileges struct {
-	Level int
+	Level ast.GrantLevelType
 	privs map[mysql.PrivilegeType]bool
 }
 
@@ -52,11 +52,11 @@ func (ps *privileges) add(p mysql.PrivilegeType) {
 
 func (ps *privileges) String() string {
 	switch ps.Level {
-	case coldef.GrantLevelGlobal:
+	case ast.GrantLevelGlobal:
 		return ps.globalPrivToString()
-	case coldef.GrantLevelDB:
+	case ast.GrantLevelDB:
 		return ps.dbPrivToString()
-	case coldef.GrantLevelTable:
+	case ast.GrantLevelTable:
 		return ps.tablePrivToString()
 	}
 	return ""
@@ -246,7 +246,7 @@ func (p *UserPrivileges) loadGlobalPrivileges(ctx context.Context) error {
 		return errors.Trace(err)
 	}
 	defer rs.Close()
-	ps := &privileges{Level: coldef.GrantLevelGlobal}
+	ps := &privileges{Level: ast.GrantLevelGlobal}
 	fs, err := rs.Fields()
 	if err != nil {
 		return errors.Trace(err)
@@ -303,7 +303,7 @@ func (p *UserPrivileges) loadDBScopePrivileges(ctx context.Context) error {
 		}
 		// DB
 		dbStr := row.Data[1].GetString()
-		ps[dbStr] = &privileges{Level: coldef.GrantLevelDB}
+		ps[dbStr] = &privileges{Level: ast.GrantLevelDB}
 		for i := dbTablePrivColumnStartIndex; i < len(fs); i++ {
 			d := row.Data[i]
 			if d.Kind() != types.KindMysqlEnum {
@@ -350,7 +350,7 @@ func (p *UserPrivileges) loadTableScopePrivileges(ctx context.Context) error {
 		if !ok {
 			ps[dbStr] = make(map[string]*privileges)
 		}
-		ps[dbStr][tblStr] = &privileges{Level: coldef.GrantLevelTable}
+		ps[dbStr][tblStr] = &privileges{Level: ast.GrantLevelTable}
 		// Table_priv
 		tblPrivs := row.Data[6].GetMysqlSet()
 		pvs := strings.Split(tblPrivs.Name, ",")
diff --git a/table/table.go b/table/table.go
index 17b8aef96e9ba..6f79aa153e62f 100644
--- a/table/table.go
+++ b/table/table.go
@@ -18,8 +18,6 @@
 package table
 
 import (
-	"fmt"
-
 	"github.com/juju/errors"
 	"github.com/pingcap/tidb/column"
 	"github.com/pingcap/tidb/context"
@@ -28,7 +26,6 @@ import (
 	"github.com/pingcap/tidb/meta/autoid"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/mysql"
-	"github.com/pingcap/tidb/sessionctx/db"
 	"github.com/pingcap/tidb/util/types"
 )
 
@@ -93,33 +90,6 @@ type Table interface {
 // Currently, it is assigned to tables.TableFromMeta in tidb package's init function.
 var TableFromMeta func(alloc autoid.Allocator, tblInfo *model.TableInfo) (Table, error)
 
-// Ident is the table identifier composed of schema name and table name.
-// TODO: Move out
-type Ident struct {
-	Schema model.CIStr
-	Name   model.CIStr
-}
-
-// Full returns an Ident which set schema to the current schema if it is empty.
-func (i Ident) Full(ctx context.Context) (full Ident) {
-	full.Name = i.Name
-	full.Schema = i.Schema
-	if i.Schema.O != "" {
-		full.Schema = i.Schema
-	} else {
-		full.Schema = model.NewCIStr(db.GetCurrentSchema(ctx))
-	}
-	return
-}
-
-// String implements fmt.Stringer interface
-func (i Ident) String() string {
-	if i.Schema.O == "" {
-		return i.Name.O
-	}
-	return fmt.Sprintf("%s.%s", i.Schema, i.Name)
-}
-
 // GetColDefaultValue gets default value of the column.
 func GetColDefaultValue(ctx context.Context, col *model.ColumnInfo) (types.Datum, bool, error) {
 	// Check no default value flag.
diff --git a/table/table_test.go b/table/table_test.go
index 9727d4a9a10ad..669d225d448c7 100644
--- a/table/table_test.go
+++ b/table/table_test.go
@@ -18,12 +18,12 @@ import (
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb"
+	"github.com/pingcap/tidb/ast"
 	"github.com/pingcap/tidb/context"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/sessionctx/db"
 	"github.com/pingcap/tidb/store/localstore"
 	"github.com/pingcap/tidb/store/localstore/goleveldb"
-	"github.com/pingcap/tidb/table"
 )
 
 func TestT(t *testing.T) {
@@ -36,7 +36,7 @@ type testSuite struct {
 }
 
 func (*testSuite) TestT(c *C) {
-	var ident = table.Ident{
+	var ident = ast.Ident{
 		Name: model.NewCIStr("t"),
 	}
 	c.Assert(ident.String(), Not(Equals), "")