Merge pull request pingcap#985 from pingcap/shenli/index-option

*: Add index option in IndexInfo

ast/ddl.go

@@ -14,6 +14,7 @@
 package ast
 
 import (
+	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/util/types"
 )
 
@@ -198,15 +199,6 @@ func (n *ColumnOption) Accept(v Visitor) (Node, bool) {
 	return v.Leave(n)
 }
 
-// IndexType is the type of index
-type IndexType int
-
-// IndexTypes
-const (
-	IndexTypeBtree = iota + 1
-	IndexTypeHash
-)
-
 // IndexOption is the index options.
 //    KEY_BLOCK_SIZE [=] value
 //  | index_type
@@ -217,7 +209,7 @@ type IndexOption struct {
 	node
 
 	KeyBlockSize uint64
-	Tp           IndexType
+	Tp           model.IndexType
 	Comment      string
 }
 
@@ -259,6 +251,9 @@ type Constraint struct {
 
 	// Used for foreign key.
 	Refer *ReferenceDef
+
+	// Index Options
+	Option *IndexOption
 }
 
 // Accept implements Node Accept interface.
@@ -282,6 +277,13 @@ func (n *Constraint) Accept(v Visitor) (Node, bool) {
 		}
 		n.Refer = node.(*ReferenceDef)
 	}
+	if n.Option != nil {
+		node, ok := n.Option.Accept(v)
+		if !ok {
+			return n, false
+		}
+		n.Option = node.(*IndexOption)
+	}
 	return v.Leave(n)
 }
 

ddl/ddl.go

@@ -44,7 +44,7 @@ import (
 type DDL interface {
 	CreateSchema(ctx context.Context, name model.CIStr, charsetInfo *ast.CharsetOpt) error
 	DropSchema(ctx context.Context, schema model.CIStr) error
-	CreateTable(ctx context.Context, ident ast.Ident, cols []*ast.ColumnDef, constrs []*ast.Constraint) error
+	CreateTable(ctx context.Context, ident ast.Ident, cols []*ast.ColumnDef, constrs []*ast.Constraint, options []*ast.TableOption) 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
@@ -680,6 +680,13 @@ func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constrai
 		case ast.ConstraintUniq, ast.ConstraintUniqKey, ast.ConstraintUniqIndex:
 			idxInfo.Unique = true
 		}
+		if constr.Option != nil {
+			idxInfo.Comment = constr.Option.Comment
+			idxInfo.Tp = constr.Option.Tp
+		} else {
+			// Use btree as default index type.
+			idxInfo.Tp = model.IndexTypeBtree
+		}
 		idxInfo.ID, err = d.genGlobalID()
 		if err != nil {
 			return nil, errors.Trace(err)
@@ -689,7 +696,7 @@ func (d *ddl) buildTableInfo(tableName model.CIStr, cols []*column.Col, constrai
 	return
 }
 
-func (d *ddl) CreateTable(ctx context.Context, ident ast.Ident, colDefs []*ast.ColumnDef, constraints []*ast.Constraint) (err error) {
+func (d *ddl) CreateTable(ctx context.Context, ident ast.Ident, colDefs []*ast.ColumnDef, constraints []*ast.Constraint, options []*ast.TableOption) (err error) {
 	is := d.GetInformationSchema()
 	schema, ok := is.SchemaByName(ident.Schema)
 	if !ok {

executor/executor_ddl.go

@@ -108,7 +108,7 @@ func (e *DDLExec) executeCreateDatabase(s *ast.CreateDatabaseStmt) error {
 
 func (e *DDLExec) executeCreateTable(s *ast.CreateTableStmt) error {
 	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)
+	err := sessionctx.GetDomain(e.ctx).DDL().CreateTable(e.ctx, ident, s.Cols, s.Constraints, s.Options)
 	if terror.ErrorEqual(err, infoschema.TableExists) {
 		if s.IfNotExists {
 			return nil

executor/show.go

@@ -252,9 +252,9 @@ func (e *ShowExec) fetchShowIndex() error {
 				subPart,          // Sub_part
 				nil,              // Packed
 				"YES",            // Null
-				"BTREE",          // Index_type
+				idx.Tp.String(),  // Index_type
 				"",               // Comment
-				"",               // Index_comment
+				idx.Comment,      // Index_comment
 			)
 			e.rows = append(e.rows, &Row{Data: data})
 		}

executor/show_test.go

@@ -37,4 +37,18 @@ func (s *testSuite) TestShow(c *C) {
 	testSQL = "SHOW VARIABLES LIKE 'character_set_results';"
 	result = tk.MustQuery(testSQL)
 	c.Check(result.Rows(), HasLen, 1)
+
+	// Test case for index type and comment
+	tk.MustExec(`create table show_index (c int, index cIdx using hash (c) comment "index_comment_for_cIdx");`)
+	testSQL = "SHOW index from show_index;"
+	result = tk.MustQuery(testSQL)
+	c.Check(result.Rows(), HasLen, 1)
+	expectedRow := []interface{}{
+		"show_index", int64(1), "cIdx", int64(1), "c", "utf8_bin",
+		int64(0), nil, nil, "YES", "HASH", "", "index_comment_for_cIdx"}
+	row := result.Rows()[0]
+	c.Check(row, HasLen, len(expectedRow))
+	for i, r := range row {
+		c.Check(r, Equals, expectedRow[i])
+	}
 }

model/model.go

@@ -83,6 +83,7 @@ type TableInfo struct {
 	Indices    []*IndexInfo  `json:"index_info"`
 	State      SchemaState   `json:"state"`
 	PKIsHandle bool          `json:"pk_is_handle"`
+	Comment    string        `json:"comment"`
 }
 
 // Clone clones TableInfo.
@@ -114,6 +115,26 @@ func (i *IndexColumn) Clone() *IndexColumn {
 	return &ni
 }
 
+// IndexType is the type of index
+type IndexType int
+
+// String implements Stringer interface.
+func (t IndexType) String() string {
+	switch t {
+	case IndexTypeBtree:
+		return "BTREE"
+	case IndexTypeHash:
+		return "HASH"
+	}
+	return ""
+}
+
+// IndexTypes
+const (
+	IndexTypeBtree IndexType = iota + 1
+	IndexTypeHash
+)
+
 // IndexInfo provides meta data describing a DB index.
 // It corresponds to the statement `CREATE INDEX Name ON Table (Column);`
 // See: https://dev.mysql.com/doc/refman/5.7/en/create-index.html
@@ -125,6 +146,8 @@ type IndexInfo struct {
 	Unique  bool           `json:"is_unique"`  // Whether the index is unique.
 	Primary bool           `json:"is_primary"` // Whether the index is primary key.
 	State   SchemaState    `json:"state"`
+	Comment string         `json:"comment"`    // Comment
+	Tp      IndexType      `json:"index_type"` // Index type: Btree or Hash
 }
 
 // Clone clones IndexInfo.