infoschema: load auto id related changes for multi-schema-change diff (…

…#52967)

close #47899

pkg/ddl/multi_schema_change.go

@@ -127,6 +127,7 @@ func onMultiSchemaChange(w *worker, d *ddlCtx, t *meta.Meta, job *model.Job) (ve
 		subJobs := make([]model.SubJob, len(job.MultiSchemaInfo.SubJobs))
 		// Step the sub-jobs to the non-revertible states all at once.
 		// We only generate 1 schema version for these sub-job.
+		actionTypes := make([]model.ActionType, 0, len(job.MultiSchemaInfo.SubJobs))
 		for i, sub := range job.MultiSchemaInfo.SubJobs {
 			if sub.IsFinished() {
 				continue
@@ -144,13 +145,36 @@ func onMultiSchemaChange(w *worker, d *ddlCtx, t *meta.Meta, job *model.Job) (ve
 			sub.FromProxyJob(&proxyJob, proxyJobVer)
 			if err != nil || proxyJob.Error != nil {
 				for j := i - 1; j >= 0; j-- {
+					// TODO if some sub-job is finished, this will empty them
+					// also some sub-job cannot be rollback completely, maybe keep them?
 					job.MultiSchemaInfo.SubJobs[j] = &subJobs[j]
 				}
 				handleRevertibleException(job, sub, proxyJob.Error)
 				// The TableInfo and sub-jobs should be restored
 				// because some schema changes update the transaction aggressively.
+				// TODO this error handling cannot handle below case:
+				// suppose the job is for "alter table t auto_increment = 100, add column c int".
+				// if we fail on "add column c int", the allocator is rebased to 100
+				// which cannot be rollback, but it's table-info.AutoIncID is rollback by below call.
+				// TODO we should also change schema diff of 'ver' if len(actionTypes) > 1.
 				return updateVersionAndTableInfo(d, t, job, tblInfo, true)
 			}
+			actionTypes = append(actionTypes, sub.Type)
+		}
+		if len(actionTypes) > 1 {
+			// only single table schema changes can be put into a multi-schema-change
+			// job except AddForeignKey which is handled separately in the first loop.
+			// so this diff is enough, but it wound be better to accumulate all the diffs,
+			// and then merge them into a single diff.
+			if err = t.SetSchemaDiff(&model.SchemaDiff{
+				Version:        ver,
+				Type:           job.Type,
+				TableID:        job.TableID,
+				SchemaID:       job.SchemaID,
+				SubActionTypes: actionTypes,
+			}); err != nil {
+				return ver, err
+			}
 		}
 		// All the sub-jobs are non-revertible.
 		job.MarkNonRevertible()

pkg/infoschema/BUILD.bazel

@@ -77,6 +77,7 @@ go_test(
     timeout = "short",
     srcs = [
         "bench_test.go",
+        "builder_test.go",
         "infoschema_test.go",
         "infoschema_v2_test.go",
         "main_test.go",
@@ -85,7 +86,7 @@ go_test(
     ],
     embed = [":infoschema"],
     flaky = True,
-    shard_count = 19,
+    shard_count = 20,
     deps = [
         "//pkg/ddl/placement",
         "//pkg/domain",

pkg/infoschema/builder.go

@@ -369,7 +369,7 @@ func (b *Builder) updateBundleForTableUpdate(diff *model.SchemaDiff, newTableID,
 
 func dropTableForUpdate(b *Builder, newTableID, oldTableID int64, dbInfo *model.DBInfo, diff *model.SchemaDiff) ([]int64, autoid.Allocators, error) {
 	tblIDs := make([]int64, 0, 2)
-	var newAllocs autoid.Allocators
+	var keptAllocs autoid.Allocators
 	// We try to reuse the old allocator, so the cached auto ID can be reused.
 	if tableIDIsValid(oldTableID) {
 		if oldTableID == newTableID &&
@@ -386,14 +386,14 @@ func dropTableForUpdate(b *Builder, newTableID, oldTableID int64, dbInfo *model.
 			// which may have AutoID not connected to tableID
 			// TODO: can there be _tidb_rowid AutoID per partition?
 			oldAllocs, _ := allocByID(b, oldTableID)
-			newAllocs = filterAllocators(diff, oldAllocs)
+			keptAllocs = getKeptAllocators(diff, oldAllocs)
 		}
 
 		tmpIDs := tblIDs
 		if (diff.Type == model.ActionRenameTable || diff.Type == model.ActionRenameTables) && diff.OldSchemaID != diff.SchemaID {
 			oldDBInfo, ok := oldSchemaInfo(b, diff)
 			if !ok {
-				return nil, newAllocs, ErrDatabaseNotExists.GenWithStackByArgs(
+				return nil, keptAllocs, ErrDatabaseNotExists.GenWithStackByArgs(
 					fmt.Sprintf("(Schema ID %d)", diff.OldSchemaID),
 				)
 			}
@@ -407,7 +407,7 @@ func dropTableForUpdate(b *Builder, newTableID, oldTableID int64, dbInfo *model.
 			tblIDs = tmpIDs
 		}
 	}
-	return tblIDs, newAllocs, nil
+	return tblIDs, keptAllocs, nil
 }
 
 func (b *Builder) applyTableUpdate(m *meta.Meta, diff *model.SchemaDiff) ([]int64, error) {
@@ -438,16 +438,33 @@ func (b *Builder) applyTableUpdate(m *meta.Meta, diff *model.SchemaDiff) ([]int6
 	return tblIDs, nil
 }
 
-func filterAllocators(diff *model.SchemaDiff, oldAllocs autoid.Allocators) autoid.Allocators {
-	var newAllocs autoid.Allocators
+// getKeptAllocators get allocators that is not changed by the DDL.
+func getKeptAllocators(diff *model.SchemaDiff, oldAllocs autoid.Allocators) autoid.Allocators {
+	var autoIDChanged, autoRandomChanged bool
 	switch diff.Type {
 	case model.ActionRebaseAutoID, model.ActionModifyTableAutoIdCache:
+		autoIDChanged = true
+	case model.ActionRebaseAutoRandomBase:
+		autoRandomChanged = true
+	case model.ActionMultiSchemaChange:
+		for _, t := range diff.SubActionTypes {
+			switch t {
+			case model.ActionRebaseAutoID, model.ActionModifyTableAutoIdCache:
+				autoIDChanged = true
+			case model.ActionRebaseAutoRandomBase:
+				autoRandomChanged = true
+			}
+		}
+	}
+	var newAllocs autoid.Allocators
+	switch {
+	case autoIDChanged:
 		// Only drop auto-increment allocator.
 		newAllocs = oldAllocs.Filter(func(a autoid.Allocator) bool {
 			tp := a.GetType()
 			return tp != autoid.RowIDAllocType && tp != autoid.AutoIncrementType
 		})
-	case model.ActionRebaseAutoRandomBase:
+	case autoRandomChanged:
 		// Only drop auto-random allocator.
 		newAllocs = oldAllocs.Filter(func(a autoid.Allocator) bool {
 			tp := a.GetType()

pkg/infoschema/builder_test.go

@@ -0,0 +1,94 @@
+// Copyright 2024 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,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package infoschema
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/pingcap/tidb/pkg/meta/autoid"
+	"github.com/pingcap/tidb/pkg/parser/model"
+	"github.com/stretchr/testify/require"
+)
+
+type mockAlloc struct {
+	autoid.Allocator
+	tp autoid.AllocatorType
+}
+
+func (m *mockAlloc) GetType() autoid.AllocatorType {
+	return m.tp
+}
+
+func TestGetKeptAllocators(t *testing.T) {
+	checkAllocators := func(allocators autoid.Allocators, expected []autoid.AllocatorType) {
+		require.Len(t, allocators.Allocs, len(expected))
+		for i, tp := range expected {
+			require.Equal(t, tp, allocators.Allocs[i].GetType())
+		}
+	}
+	allocators := autoid.Allocators{Allocs: []autoid.Allocator{
+		&mockAlloc{tp: autoid.RowIDAllocType},
+		&mockAlloc{tp: autoid.AutoIncrementType},
+		&mockAlloc{tp: autoid.AutoRandomType},
+	}}
+	cases := []struct {
+		diff     *model.SchemaDiff
+		expected []autoid.AllocatorType
+	}{
+		{
+			diff:     &model.SchemaDiff{Type: model.ActionTruncateTable},
+			expected: []autoid.AllocatorType{autoid.RowIDAllocType, autoid.AutoIncrementType, autoid.AutoRandomType},
+		},
+		{
+			diff:     &model.SchemaDiff{Type: model.ActionRebaseAutoID},
+			expected: []autoid.AllocatorType{autoid.AutoRandomType},
+		},
+		{
+			diff:     &model.SchemaDiff{Type: model.ActionModifyTableAutoIdCache},
+			expected: []autoid.AllocatorType{autoid.AutoRandomType},
+		},
+		{
+			diff:     &model.SchemaDiff{Type: model.ActionRebaseAutoRandomBase},
+			expected: []autoid.AllocatorType{autoid.RowIDAllocType, autoid.AutoIncrementType},
+		},
+		{
+			diff: &model.SchemaDiff{Type: model.ActionMultiSchemaChange,
+				SubActionTypes: []model.ActionType{model.ActionAddColumn, model.ActionRebaseAutoID}},
+			expected: []autoid.AllocatorType{autoid.AutoRandomType},
+		},
+		{
+			diff: &model.SchemaDiff{Type: model.ActionMultiSchemaChange,
+				SubActionTypes: []model.ActionType{model.ActionModifyTableAutoIdCache}},
+			expected: []autoid.AllocatorType{autoid.AutoRandomType},
+		},
+		{
+			diff: &model.SchemaDiff{Type: model.ActionMultiSchemaChange,
+				SubActionTypes: []model.ActionType{model.ActionRebaseAutoRandomBase}},
+			expected: []autoid.AllocatorType{autoid.RowIDAllocType, autoid.AutoIncrementType},
+		},
+		{
+			diff: &model.SchemaDiff{Type: model.ActionMultiSchemaChange,
+				SubActionTypes: []model.ActionType{model.ActionAddColumn}},
+			expected: []autoid.AllocatorType{autoid.RowIDAllocType, autoid.AutoIncrementType, autoid.AutoRandomType},
+		},
+	}
+	for i, c := range cases {
+		t.Run(fmt.Sprintf("case %d", i), func(t *testing.T) {
+			res := getKeptAllocators(c.diff, allocators)
+			checkAllocators(res, c.expected)
+		})
+	}
+}

pkg/parser/model/ddl.go

@@ -1138,6 +1138,12 @@ type SchemaDiff struct {
 	SchemaID int64      `json:"schema_id"`
 	TableID  int64      `json:"table_id"`
 
+	// SubActionTypes is the list of action types done together within a multiple schema
+	// change job. As the job might contain multiple steps that changes schema version,
+	// if some step only contains one action, Type will be that action, and SubActionTypes
+	// will be empty.
+	// for other types of job, it will always be empty.
+	SubActionTypes []ActionType `json:"sub_action_types,omitempty"`
 	// OldTableID is the table ID before truncate, only used by truncate table DDL.
 	OldTableID int64 `json:"old_table_id"`
 	// OldSchemaID is the schema ID before rename table, only used by rename table DDL.

tests/integrationtest/r/ddl/multi_schema_change.result

@@ -373,12 +373,14 @@ select * from t use index (i3);
 c	d	e	f
 3	4	5	6
 drop table if exists t;
-create table t (a int auto_increment primary key, b int);
-alter table t modify column b tinyint, auto_increment = 100;
-insert into t (b) values (1);
+create table t (a int auto_increment primary key, b int) auto_id_cache = 100;
+insert into t(b) values(1);
+alter table t modify column b tinyint, auto_increment = 200;
+insert into t (b) values (2);
 select * from t;
 a	b
-100	1
+1	1
+200	2
 drop table if exists t;
 create table t (a int auto_increment primary key, b int);
 alter table t auto_increment = 110, auto_increment = 90;

tests/integrationtest/t/ddl/multi_schema_change.test

@@ -312,9 +312,10 @@ select * from t use index (i3);
 
 # TestMultiSchemaChangeTableOption
 drop table if exists t;
-create table t (a int auto_increment primary key, b int);
-alter table t modify column b tinyint, auto_increment = 100;
-insert into t (b) values (1);
+create table t (a int auto_increment primary key, b int) auto_id_cache = 100;
+insert into t(b) values(1);
+alter table t modify column b tinyint, auto_increment = 200;
+insert into t (b) values (2);
 select * from t;
 drop table if exists t;
 create table t (a int auto_increment primary key, b int);