ddl: support alter algorithm INPLACE/INSTANT

ddl/db_integration_test.go

@@ -1210,3 +1210,79 @@ func (s *testIntegrationSuite) TestAlterColumn(c *C) {
 	_, err = s.tk.Exec("alter table mc modify column a bigint auto_increment") // Adds auto_increment should throw error
 	c.Assert(err, NotNil)
 }
+
+func (s *testIntegrationSuite) assertWarningExec(c *C, sql string, expectedWarn *terror.Error) {
+	_, err := s.tk.Exec(sql)
+	c.Assert(err, IsNil)
+	st := s.tk.Se.GetSessionVars().StmtCtx
+	c.Assert(st.WarningCount(), Equals, uint16(1))
+	c.Assert(expectedWarn.Equal(st.GetWarnings()[0].Err), IsTrue, Commentf("error:%v", err))
+}
+
+func (s *testIntegrationSuite) assertAlterWarnExec(c *C, sql string) {
+	s.assertWarningExec(c, sql, ddl.ErrAlterOperationNotSupported)
+}
+
+func (s *testIntegrationSuite) TestAlterAlgorithm(c *C) {
+	s.tk = testkit.NewTestKit(c, s.store)
+	s.tk.MustExec("use test")
+	s.tk.MustExec("drop table if exists t")
+	s.tk.MustExec("drop table if exists t1")
+	defer s.tk.MustExec("drop table if exists t")
+
+	s.tk.MustExec(`create table t(
+	a int, 
+	b varchar(100), 
+	c int, 
+	INDEX idx_c(c)) PARTITION BY RANGE ( a ) (
+	PARTITION p0 VALUES LESS THAN (6),
+		PARTITION p1 VALUES LESS THAN (11),
+		PARTITION p2 VALUES LESS THAN (16),
+		PARTITION p3 VALUES LESS THAN (21)
+	)`)
+	s.assertAlterWarnExec(c, "alter table t modify column a bigint, ALGORITHM=INPLACE;")
+	s.tk.MustExec("alter table t modify column a bigint, ALGORITHM=INPLACE, ALGORITHM=INSTANT;")
+	s.tk.MustExec("alter table t modify column a bigint, ALGORITHM=DEFAULT;")
+
+	// Test add/drop index
+	s.assertAlterWarnExec(c, "alter table t add index idx_b(b), ALGORITHM=INSTANT")
+	s.assertAlterWarnExec(c, "alter table t add index idx_b1(b), ALGORITHM=COPY")
+	s.tk.MustExec("alter table t add index idx_b2(b), ALGORITHM=INPLACE")
+	s.assertAlterWarnExec(c, "alter table t drop index idx_b, ALGORITHM=INPLACE")
+	s.assertAlterWarnExec(c, "alter table t drop index idx_b1, ALGORITHM=COPY")
+	s.tk.MustExec("alter table t drop index idx_b2, ALGORITHM=INSTANT")
+
+	// Test rename
+	s.assertAlterWarnExec(c, "alter table t rename to t1, ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t1 rename to t, ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t rename to t1, ALGORITHM=INSTANT")
+	s.tk.MustExec("alter table t1 rename to t, ALGORITHM=DEFAULT")
+
+	// Test rename index
+	s.assertAlterWarnExec(c, "alter table t rename index idx_c to idx_c1, ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t rename index idx_c1 to idx_c, ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t rename index idx_c to idx_c1, ALGORITHM=INSTANT")
+	s.tk.MustExec("alter table t rename index idx_c1 to idx_c, ALGORITHM=DEFAULT")
+
+	// partition.
+	s.assertAlterWarnExec(c, "alter table t truncate partition p1, ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t truncate partition p2, ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t truncate partition p3, ALGORITHM=INSTANT")
+
+	s.assertAlterWarnExec(c, "alter table t add partition (partition p4 values less than (2002)), ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t add partition (partition p5 values less than (3002)), ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t add partition (partition p6 values less than (4002)), ALGORITHM=INSTANT")
+
+	s.assertAlterWarnExec(c, "alter table t drop partition p4, ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t drop partition p5, ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t drop partition p6, ALGORITHM=INSTANT")
+
+	// Table options
+	s.assertAlterWarnExec(c, "alter table t comment = 'test', ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t comment = 'test', ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t comment = 'test', ALGORITHM=INSTANT")
+
+	s.assertAlterWarnExec(c, "alter table t default charset = utf8mb4, ALGORITHM=COPY")
+	s.assertAlterWarnExec(c, "alter table t default charset = utf8mb4, ALGORITHM=INPLACE")
+	s.tk.MustExec("alter table t default charset = utf8mb4, ALGORITHM=INSTANT")
+}

ddl/ddl.go

@@ -203,6 +203,8 @@ var (
 	ErrCoalesceOnlyOnHashPartition = terror.ClassDDL.New(codeCoalesceOnlyOnHashPartition, mysql.MySQLErrName[mysql.ErrCoalesceOnlyOnHashPartition])
 	// ErrViewWrongList returns create view must include all columns in the select clause
 	ErrViewWrongList = terror.ClassDDL.New(codeViewWrongList, mysql.MySQLErrName[mysql.ErrViewWrongList])
+	// ErrAlterOperationNotSupported returns when alter operations is not supported.
+	ErrAlterOperationNotSupported = terror.ClassDDL.New(codeNotSupportedAlterOperation, mysql.MySQLErrName[mysql.ErrAlterOperationNotSupportedReason])
 	// ErrWrongObject returns for wrong object.
 	ErrWrongObject = terror.ClassDDL.New(codeErrWrongObject, mysql.MySQLErrName[mysql.ErrWrongObject])
 )
@@ -685,6 +687,7 @@ const (
 	codeWarnDataTruncated                      = terror.ErrCode(mysql.WarnDataTruncated)
 	codeCoalesceOnlyOnHashPartition            = terror.ErrCode(mysql.ErrCoalesceOnlyOnHashPartition)
 	codeUnknownPartition                       = terror.ErrCode(mysql.ErrUnknownPartition)
+	codeNotSupportedAlterOperation             = terror.ErrCode(mysql.ErrAlterOperationNotSupportedReason)
 )
 
 func init() {
@@ -736,6 +739,7 @@ func init() {
 		codeWarnDataTruncated:                      mysql.WarnDataTruncated,
 		codeCoalesceOnlyOnHashPartition:            mysql.ErrCoalesceOnlyOnHashPartition,
 		codeUnknownPartition:                       mysql.ErrUnknownPartition,
+		codeNotSupportedAlterOperation:             mysql.ErrAlterOperationNotSupportedReason,
 		codeErrWrongObject:                         mysql.ErrWrongObject,
 	}
 	terror.ErrClassToMySQLCodes[terror.ClassDDL] = ddlMySQLErrCodes

ddl/ddl_algorithm.go

@@ -0,0 +1,72 @@
+// Copyright 2018 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/parser/ast"
+)
+
+// AlterAlgorithm is used to store supported alter algorithm.
+// For now, TiDB only support AlterAlgorithmInplace and AlterAlgorithmInstant.
+// The most alter operations are using instant algorithm, and only the add index is using inplace(not really inplace,
+// because we never block the DML but costs some time to backfill the index data)
+// See https://dev.mysql.com/doc/refman/8.0/en/alter-table.html#alter-table-performance.
+type AlterAlgorithm struct {
+	supported []ast.AlterAlgorithm
+	// If the alter algorithm is not given, the defAlgorithm will be used.
+	defAlgorithm ast.AlterAlgorithm
+}
+
+var (
+	instantAlgorithm = &AlterAlgorithm{
+		supported:    []ast.AlterAlgorithm{ast.AlterAlgorithmInstant},
+		defAlgorithm: ast.AlterAlgorithmInstant,
+	}
+
+	inplaceAlgorithm = &AlterAlgorithm{
+		supported:    []ast.AlterAlgorithm{ast.AlterAlgorithmInplace},
+		defAlgorithm: ast.AlterAlgorithmInplace,
+	}
+
+	defaultAlgorithm = ast.AlterAlgorithmInstant
+)
+
+func getProperAlgorithm(specify ast.AlterAlgorithm, algorithm *AlterAlgorithm) (ast.AlterAlgorithm, error) {
+	if specify == ast.AlterAlgorithmDefault {
+		return algorithm.defAlgorithm, nil
+	}
+
+	for _, a := range algorithm.supported {
+		if specify == a {
+			return specify, nil
+		}
+	}
+
+	return algorithm.defAlgorithm, ErrAlterOperationNotSupported.GenWithStackByArgs(fmt.Sprintf("ALGORITHM=%s", specify), fmt.Sprintf("Cannot alter table by %s", specify), fmt.Sprintf("ALGORITHM=%s", algorithm.defAlgorithm))
+}
+
+// ResolveAlterAlgorithm resolves the algorithm of the alterSpec.
+// If specify algorithm is not supported by the alter action, errAlterOperationNotSupported will be returned.
+// If specify is the ast.AlterAlgorithmDefault, then the default algorithm of the alter action will be returned.
+func ResolveAlterAlgorithm(alterSpec *ast.AlterTableSpec, specify ast.AlterAlgorithm) (ast.AlterAlgorithm, error) {
+	switch alterSpec.Tp {
+	// For now, TiDB only support inplace algorithm and instant algorithm.
+	case ast.AlterTableAddConstraint:
+		return getProperAlgorithm(specify, inplaceAlgorithm)
+	default:
+		return getProperAlgorithm(specify, instantAlgorithm)
+	}
+}

ddl/ddl_algorithm_test.go

@@ -0,0 +1,107 @@
+// Copyright 2018 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_test
+
+import (
+	. "github.com/pingcap/check"
+	"github.com/pingcap/parser/ast"
+	"github.com/pingcap/tidb/ddl"
+)
+
+var _ = Suite(&testDDLAlgorithmSuite{})
+
+var (
+	allAlgorithm = []ast.AlterAlgorithm{ast.AlterAlgorithmCopy,
+		ast.AlterAlgorithmInplace, ast.AlterAlgorithmInstant}
+)
+
+type testDDLAlgorithmSuite struct{}
+
+type testCase struct {
+	alterSpec          ast.AlterTableSpec
+	supportedAlgorithm []ast.AlterAlgorithm
+	defAlgorithm       ast.AlterAlgorithm
+}
+
+func (s *testDDLAlgorithmSuite) TestFindAlterAlgorithm(c *C) {
+	instantAlgorithm := []ast.AlterAlgorithm{ast.AlterAlgorithmInstant}
+	inplaceAlgorithm := []ast.AlterAlgorithm{ast.AlterAlgorithmInplace}
+
+	testCases := []testCase{
+		{ast.AlterTableSpec{Tp: ast.AlterTableAddConstraint}, inplaceAlgorithm, ast.AlterAlgorithmInplace},
+		{ast.AlterTableSpec{Tp: ast.AlterTableAddColumns}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableDropColumn}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableDropPrimaryKey}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableDropIndex}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableDropForeignKey}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableRenameTable}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableRenameIndex}, instantAlgorithm, ast.AlterAlgorithmInstant},
+
+		// Alter table options.
+		{ast.AlterTableSpec{Tp: ast.AlterTableOption, Options: []*ast.TableOption{{Tp: ast.TableOptionShardRowID}}}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableOption, Options: []*ast.TableOption{{Tp: ast.TableOptionAutoIncrement}}}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableOption, Options: []*ast.TableOption{{Tp: ast.TableOptionComment}}}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableOption, Options: []*ast.TableOption{{Tp: ast.TableOptionCharset}}}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableOption, Options: []*ast.TableOption{{Tp: ast.TableOptionCollate}}}, instantAlgorithm, ast.AlterAlgorithmInstant},
+
+		// TODO: after we support migrate the data of partitions, change below cases.
+		{ast.AlterTableSpec{Tp: ast.AlterTableCoalescePartitions}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableAddPartitions}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableDropPartition}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableTruncatePartition}, instantAlgorithm, ast.AlterAlgorithmInstant},
+
+		// TODO: after we support lock a table, change the below case.
+		{ast.AlterTableSpec{Tp: ast.AlterTableLock}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		// TODO: after we support changing the column type, below cases need to change.
+		{ast.AlterTableSpec{Tp: ast.AlterTableModifyColumn}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableChangeColumn}, instantAlgorithm, ast.AlterAlgorithmInstant},
+		{ast.AlterTableSpec{Tp: ast.AlterTableAlterColumn}, instantAlgorithm, ast.AlterAlgorithmInstant},
+	}
+
+	for _, tc := range testCases {
+		runAlterAlgorithmTestCases(c, &tc)
+	}
+}
+
+func runAlterAlgorithmTestCases(c *C, tc *testCase) {
+	algorithm, err := ddl.ResolveAlterAlgorithm(&tc.alterSpec, ast.AlterAlgorithmDefault)
+	c.Assert(err, IsNil)
+	c.Assert(algorithm, Equals, tc.defAlgorithm)
+
+	unsupported := make([]ast.AlterAlgorithm, 0, len(allAlgorithm))
+Loop:
+	for _, alm := range allAlgorithm {
+		for _, almSupport := range tc.supportedAlgorithm {
+			if alm == almSupport {
+				continue Loop
+			}
+		}
+
+		unsupported = append(unsupported, alm)
+	}
+
+	// Test supported.
+	for _, alm := range tc.supportedAlgorithm {
+		algorithm, err = ddl.ResolveAlterAlgorithm(&tc.alterSpec, alm)
+		c.Assert(err, IsNil)
+		c.Assert(algorithm, Equals, alm)
+	}
+
+	// Test unsupported.
+	for _, alm := range unsupported {
+		algorithm, err = ddl.ResolveAlterAlgorithm(&tc.alterSpec, alm)
+		c.Assert(err, NotNil, Commentf("Tp:%v, alm:%s", tc.alterSpec.Tp, alm))
+		c.Assert(ddl.ErrAlterOperationNotSupported.Equal(err), IsTrue)
+	}
+}

ddl/ddl_api.go

@@ -1424,10 +1424,16 @@ func getCharsetAndCollateInTableOption(startIdx int, options []*ast.TableOption)
 	return
 }
 
-func (d *ddl) AlterTable(ctx sessionctx.Context, ident ast.Ident, specs []*ast.AlterTableSpec) (err error) {
-	// Only handle valid specs.
+// resolveAlterTableSpec resolves alter table algorithm and removes ignore table spec in specs.
+// returns valied specs, and the occured error.
+func resolveAlterTableSpec(ctx sessionctx.Context, specs []*ast.AlterTableSpec) ([]*ast.AlterTableSpec, error) {
 	validSpecs := make([]*ast.AlterTableSpec, 0, len(specs))
+	algorithm := ast.AlterAlgorithmDefault
 	for _, spec := range specs {
+		if spec.Tp == ast.AlterTableAlgorithm {
+			// Find the last AlterTableAlgorithm.
+			algorithm = spec.Algorithm
+		}
 		if isIgnorableSpec(spec.Tp) {
 			continue
 		}
@@ -1437,7 +1443,29 @@ func (d *ddl) AlterTable(ctx sessionctx.Context, ident ast.Ident, specs []*ast.A
 	if len(validSpecs) != 1 {
 		// TODO: Hanlde len(validSpecs) == 0.
 		// Now we only allow one schema changing at the same time.
-		return errRunMultiSchemaChanges
+		return nil, errRunMultiSchemaChanges
+	}
+
+	// Verify whether the algorithm is supported.
+	for _, spec := range validSpecs {
+		algorithm, err := ResolveAlterAlgorithm(spec, algorithm)
+		if err != nil {
+			// For the compatibility, we return warning instead of error.
+			ctx.GetSessionVars().StmtCtx.AppendError(err)
+			err = nil
+		}
+
+		spec.Algorithm = algorithm
+	}
+
+	// Only handle valid specs.
+	return validSpecs, nil
+}
+
+func (d *ddl) AlterTable(ctx sessionctx.Context, ident ast.Ident, specs []*ast.AlterTableSpec) (err error) {
+	validSpecs, err := resolveAlterTableSpec(ctx, specs)
+	if err != nil {
+		return errors.Trace(err)
 	}
 
 	is := d.infoHandle.Get()

go.mod

@@ -87,3 +87,5 @@ require (
 	sourcegraph.com/sourcegraph/appdash v0.0.0-20180531100431-4c381bd170b4
 	sourcegraph.com/sourcegraph/appdash-data v0.0.0-20151005221446-73f23eafcf67
 )
+
+replace github.com/pingcap/parser => github.com/winkyao/parser v0.0.0-20190219030644-4a96e9b20471

go.sum

@@ -171,6 +171,7 @@ github.com/ugorji/go/codec v0.0.0-20181127175209-856da096dbdf h1:BLcwkDfQ8QPXNXB
 github.com/ugorji/go/codec v0.0.0-20181127175209-856da096dbdf/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
 github.com/unrolled/render v0.0.0-20180914162206-b9786414de4d h1:ggUgChAeyge4NZ4QUw6lhHsVymzwSDJOZcE0s2X8S20=
 github.com/unrolled/render v0.0.0-20180914162206-b9786414de4d/go.mod h1:tu82oB5W2ykJRVioYsB+IQKcft7ryBr7w12qMBUPyXg=
+github.com/winkyao/parser v0.0.0-20190219030644-4a96e9b20471/go.mod h1:R7TohkGdsluhClCn0ZTwhHDjjjqoiBr6DFFAPTaFvUI=
 github.com/xiang90/probing v0.0.0-20160813154853-07dd2e8dfe18 h1:MPPkRncZLN9Kh4MEFmbnK4h3BD7AUmskWv2+EeZJCCs=
 github.com/xiang90/probing v0.0.0-20160813154853-07dd2e8dfe18/go.mod h1:UETIi67q53MR2AWcXfiuqkDkRtnGDLqkBTpCHuJHxtU=
 go.uber.org/atomic v1.3.2 h1:2Oa65PReHzfn29GpvgsYwloV9AVFHPDk8tYxt2c2tr4=