parser: support the 'create global temporary table' syntax

ast/ddl.go

@@ -933,29 +933,44 @@ func (n *ColumnDef) Validate() bool {
 	return !(generatedCol && illegalOpt4gc)
 }
 
+type TemporaryKeyword int
+
+const (
+	TemporaryNone TemporaryKeyword = iota
+	TemporaryGlobal
+	TemporaryLocal
+)
+
 // CreateTableStmt is a statement to create a table.
 // See https://dev.mysql.com/doc/refman/5.7/en/create-table.html
 type CreateTableStmt struct {
 	ddlNode
 
 	IfNotExists bool
-	IsTemporary bool
-	Table       *TableName
-	ReferTable  *TableName
-	Cols        []*ColumnDef
-	Constraints []*Constraint
-	Options     []*TableOption
-	Partition   *PartitionOptions
-	OnDuplicate OnDuplicateKeyHandlingType
-	Select      ResultSetNode
+	TemporaryKeyword
+	// Meanless when TemporaryKeyword is not TemporaryGlobal.
+	// ON COMMIT DELETE ROWS => true
+	// ON COMMIT PRESERVE ROW => false
+	OnCommitDelete bool
+	Table          *TableName
+	ReferTable     *TableName
+	Cols           []*ColumnDef
+	Constraints    []*Constraint
+	Options        []*TableOption
+	Partition      *PartitionOptions
+	OnDuplicate    OnDuplicateKeyHandlingType
+	Select         ResultSetNode
 }
 
 // Restore implements Node interface.
 func (n *CreateTableStmt) Restore(ctx *format.RestoreCtx) error {
-	if n.IsTemporary {
-		ctx.WriteKeyWord("CREATE TEMPORARY TABLE ")
-	} else {
+	switch n.TemporaryKeyword {
+	case TemporaryNone:
 		ctx.WriteKeyWord("CREATE TABLE ")
+	case TemporaryGlobal:
+		ctx.WriteKeyWord("CREATE GLOBAL TEMPORARY TABLE ")
+	case TemporaryLocal:
+		ctx.WriteKeyWord("CREATE TEMPORARY TABLE ")
 	}
 	if n.IfNotExists {
 		ctx.WriteKeyWord("IF NOT EXISTS ")
@@ -1023,6 +1038,14 @@ func (n *CreateTableStmt) Restore(ctx *format.RestoreCtx) error {
 		}
 	}
 
+	if n.TemporaryKeyword == TemporaryGlobal {
+		if n.OnCommitDelete {
+			ctx.WriteKeyWord(" ON COMMIT DELETE ROWS")
+		} else {
+			ctx.WriteKeyWord(" ON COMMIT PRESERVE ROWS")
+		}
+	}
+
 	return nil
 }
 
@@ -1082,21 +1105,24 @@ func (n *CreateTableStmt) Accept(v Visitor) (Node, bool) {
 type DropTableStmt struct {
 	ddlNode
 
-	IfExists    bool
-	Tables      []*TableName
-	IsView      bool
-	IsTemporary bool // make sense ONLY if/when IsView == false
+	IfExists         bool
+	Tables           []*TableName
+	IsView           bool
+	TemporaryKeyword // make sense ONLY if/when IsView == false
 }
 
 // Restore implements Node interface.
 func (n *DropTableStmt) Restore(ctx *format.RestoreCtx) error {
 	if n.IsView {
 		ctx.WriteKeyWord("DROP VIEW ")
 	} else {
-		if n.IsTemporary {
-			ctx.WriteKeyWord("DROP TEMPORARY TABLE ")
-		} else {
+		switch n.TemporaryKeyword {
+		case TemporaryNone:
 			ctx.WriteKeyWord("DROP TABLE ")
+		case TemporaryGlobal:
+			ctx.WriteKeyWord("DROP GLOBAL TEMPORARY TABLE ")
+		case TemporaryLocal:
+			ctx.WriteKeyWord("DROP TEMPORARY TABLE ")
 		}
 	}
 	if n.IfExists {

misc.go

@@ -529,6 +529,7 @@ var tokenMap = map[string]int{
 	"PRECEDING":                preceding,
 	"PRECISION":                precisionType,
 	"PREPARE":                  prepare,
+	"PRESERVE":                 preserve,
 	"PRIMARY":                  primary,
 	"PRIVILEGES":               privileges,
 	"PROCEDURE":                procedure,

model/model.go

@@ -335,6 +335,27 @@ type TableInfo struct {
 	// IsColumnar means the table is column-oriented.
 	// It's true when the engine of the table is TiFlash only.
 	IsColumnar bool `json:"is_columnar"`
+
+	TempTableType `json:"temp_table_type"`
+}
+
+type TempTableType byte
+
+const (
+	TempTableNone TempTableType = iota
+	TempTableGlobal
+	TempTableLocal
+)
+
+func (t TempTableType) String() string {
+	switch t {
+	case TempTableGlobal:
+		return "global"
+	case TempTableLocal:
+		return "local"
+	default:
+		return ""
+	}
 }
 
 // TableLockInfo provides meta data describing a table lock.