*: Support AlterTable with Algorithm option and fix a few things repo…

…rted by goword (pingcap#6141)

Improve the compatibility with MySQL.

ast/ddl.go

@@ -249,6 +249,7 @@ type ColumnOption struct {
 	node
 
 	Tp ColumnOptionType
+	// Expr is used for ColumnOptionDefaultValue/ColumnOptionOnUpdateColumnOptionGenerated.
 	// For ColumnOptionDefaultValue or ColumnOptionOnUpdate, it's the target value.
 	// For ColumnOptionGenerated, it's the target expression.
 	Expr ExprNode
@@ -473,8 +474,9 @@ type RenameTableStmt struct {
 
 	OldTable *TableName
 	NewTable *TableName
+
+	// TableToTables is only useful for syncer which depends heavily on tidb parser to do some dirty work for now.
 	// TODO: Refactor this when you are going to add full support for multiple schema changes.
-	// Currently it is only useful for syncer which depends heavily on tidb parser to do some dirty work.
 	TableToTables []*TableToTable
 }
 
@@ -713,6 +715,7 @@ const (
 	AlterTableRenameTable
 	AlterTableAlterColumn
 	AlterTableLock
+	AlterTableAlgorithm
 
 // TODO: Add more actions
 )

ddl/ddl_api.go

@@ -858,11 +858,18 @@ func hasAutoIncrementColumn(tbInfo *model.TableInfo) bool {
 	return false
 }
 
+// isIgnorableSpec checks if the spec type is ignorable.
+// Some specs are parsed by ignored. This is for compatibility.
+func isIgnorableSpec(tp ast.AlterTableType) bool {
+	// AlterTableLock/AlterTableAlgorithm are ignored.
+	return tp == ast.AlterTableLock || tp == ast.AlterTableAlgorithm
+}
+
 func (d *ddl) AlterTable(ctx sessionctx.Context, ident ast.Ident, specs []*ast.AlterTableSpec) (err error) {
-	// Only handle valid specs, AlterTableLock is ignored.
+	// Only handle valid specs.
 	validSpecs := make([]*ast.AlterTableSpec, 0, len(specs))
 	for _, spec := range specs {
-		if spec.Tp == ast.AlterTableLock {
+		if isIgnorableSpec(spec.Tp) {
 			continue
 		}
 		validSpecs = append(validSpecs, spec)

ddl/ddl_worker_test.go

@@ -449,3 +449,30 @@ func (s *testDDLSuite) TestCancelJob(c *C) {
 	tblInfo = testTableInfo(c, d, "t1", 3)
 	testCreateTable(c, ctx, d, dbInfo, tblInfo)
 }
+
+func (s *testDDLSuite) TestIgnorableSpec(c *C) {
+	specs := []ast.AlterTableType{
+		ast.AlterTableOption,
+		ast.AlterTableAddColumns,
+		ast.AlterTableAddConstraint,
+		ast.AlterTableDropColumn,
+		ast.AlterTableDropPrimaryKey,
+		ast.AlterTableDropIndex,
+		ast.AlterTableDropForeignKey,
+		ast.AlterTableModifyColumn,
+		ast.AlterTableChangeColumn,
+		ast.AlterTableRenameTable,
+		ast.AlterTableAlterColumn,
+	}
+	for _, spec := range specs {
+		c.Assert(isIgnorableSpec(spec), IsFalse)
+	}
+
+	ignorableSpecs := []ast.AlterTableType{
+		ast.AlterTableLock,
+		ast.AlterTableAlgorithm,
+	}
+	for _, spec := range ignorableSpecs {
+		c.Assert(isIgnorableSpec(spec), IsTrue)
+	}
+}

parser/misc.go

@@ -194,6 +194,7 @@ var tokenMap = map[string]int{
 	"CONSISTENT":        consistent,
 	"CONSTRAINT":        constraint,
 	"CONVERT":           convert,
+	"COPY":              copyKwd,
 	"COUNT":             count,
 	"CREATE":            create,
 	"CROSS":             cross,
@@ -287,6 +288,7 @@ var tokenMap = map[string]int{
 	"INDEXES":           indexes,
 	"INFILE":            infile,
 	"INNER":             inner,
+	"INPLACE":           inplace,
 	"INSERT":            insert,
 	"INT":               intType,
 	"INT1":              int1Type,

parser/parser.y

@@ -399,13 +399,15 @@ import (
 	bitOr		"BIT_OR"
 	bitXor		"BIT_XOR"
 	cast		"CAST"
+	copyKwd		"COPY"
 	count		"COUNT"
 	curTime		"CURTIME"
 	dateAdd		"DATE_ADD"
 	dateSub		"DATE_SUB"
 	extract		"EXTRACT"
 	getFormat	"GET_FORMAT"
 	groupConcat	"GROUP_CONCAT"
+	inplace 	"INPLACE"
 	min		"MIN"
 	max		"MAX"
 	now		"NOW"
@@ -1019,6 +1021,16 @@ AlterTableSpec:
 			LockType:   $1.(ast.LockType),
 		}
 	}
+| "ALGORITHM" EqOpt AlterAlgorithm
+	{
+		// Parse it and ignore it. Just for compatibility.
+		$$ = &ast.AlterTableSpec{
+			Tp:    		ast.AlterTableAlgorithm,
+		}
+	}
+
+AlterAlgorithm:
+	"DEFAULT" | "INPLACE" | "COPY"
 
 LockClauseOpt:
 	{}
@@ -2540,8 +2552,8 @@ TiDBKeyword:
 "ADMIN" | "CANCEL" | "DDL" | "JOBS" | "JOB" | "STATS" | "STATS_META" | "STATS_HISTOGRAMS" | "STATS_BUCKETS" | "STATS_HEALTHY" | "TIDB" | "TIDB_HJ" | "TIDB_SMJ" | "TIDB_INLJ"
 
 NotKeywordToken:
- "ADDDATE" | "BIT_AND" | "BIT_OR" | "BIT_XOR" | "CAST" | "COUNT" | "CURTIME" | "DATE_ADD" | "DATE_SUB" | "EXTRACT" | "GET_FORMAT" | "GROUP_CONCAT" | "MIN" | "MAX" | "NOW" | "POSITION"
-| "SUBDATE" | "SUBSTRING" | "SUM" | "TIMESTAMPADD" | "TIMESTAMPDIFF" | "TRIM"
+ "ADDDATE" | "BIT_AND" | "BIT_OR" | "BIT_XOR" | "CAST" | "COPY" | "COUNT" | "CURTIME" | "DATE_ADD" | "DATE_SUB" | "EXTRACT" | "GET_FORMAT" | "GROUP_CONCAT" 
+| "INPLACE" |"MIN" | "MAX" | "NOW" | "POSITION" | "SUBDATE" | "SUBSTRING" | "SUM" | "TIMESTAMPADD" | "TIMESTAMPDIFF" | "TRIM"
 
 /************************************************************************************
  *

parser/parser_test.go

@@ -1588,6 +1588,9 @@ func (s *testParserSuite) TestDDL(c *C) {
 		{"ALTER TABLE t ENGINE = '', ADD COLUMN a SMALLINT", true},
 		{"ALTER TABLE t default COLLATE = utf8_general_ci, ENGINE = '', ADD COLUMN a SMALLINT", true},
 		{"ALTER TABLE t shard_row_id_bits = 1", true},
+		{"ALTER TABLE `hello-world@dev`.`User` ADD COLUMN `name` mediumtext CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL , ALGORITHM = DEFAULT;", true},
+		{"ALTER TABLE `hello-world@dev`.`User` ADD COLUMN `name` mediumtext CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL , ALGORITHM = INPLACE;", true},
+		{"ALTER TABLE `hello-world@dev`.`User` ADD COLUMN `name` mediumtext CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL , ALGORITHM = COPY;", true},
 
 		// For create index statement
 		{"CREATE INDEX idx ON t (a)", true},