*: support for "admin show next_row_id"

ast/misc.go

@@ -628,6 +628,7 @@ const (
 	AdminShowDDLJobQueries
 	AdminChecksumTable
 	AdminShowSlow
+	AdminShowNextRowID
 )
 
 // HandleRange represents a range where handle value >= Begin and < End.

executor/admin_test.go

@@ -18,6 +18,7 @@ import (
 
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb/executor"
+	"github.com/pingcap/tidb/meta/autoid"
 	"github.com/pingcap/tidb/model"
 	"github.com/pingcap/tidb/table/tables"
 	"github.com/pingcap/tidb/types"
@@ -515,3 +516,45 @@ func (s *testSuite) TestAdminCheckPrimaryIndex(c *C) {
 	tk.MustExec("insert into t values(1, 1, 1), (9223372036854775807, 2, 2);")
 	tk.MustExec("admin check index t idx;")
 }
+
+func (s *testSuite) TestAdminShowNextID(c *C) {
+	step := int64(10)
+	autoIDStep := autoid.GetStep()
+	autoid.SetStep(step)
+	defer autoid.SetStep(autoIDStep)
+	tk := testkit.NewTestKit(c, s.store)
+	tk.MustExec("use test")
+	tk.MustExec("create table t(id int, c int)")
+	// Start handle is 1.
+	r := tk.MustQuery("admin show t next_row_id")
+	r.Check(testkit.Rows("test t _tidb_rowid 1"))
+	// Row ID is step + 1.
+	tk.MustExec("insert into t values(1, 1)")
+	r = tk.MustQuery("admin show t next_row_id")
+	r.Check(testkit.Rows("test t _tidb_rowid 11"))
+	// Row ID is original + step.
+	for i := 0; i < int(step); i++ {
+		tk.MustExec("insert into t values(10000, 1)")
+	}
+	r = tk.MustQuery("admin show t next_row_id")
+	r.Check(testkit.Rows("test t _tidb_rowid 21"))
+
+	// test for a table with the primary key
+	tk.MustExec("create table tt(id int primary key auto_increment, c int)")
+	// Start handle is 1.
+	r = tk.MustQuery("admin show tt next_row_id")
+	r.Check(testkit.Rows("test tt id 1"))
+	// After rebasing auto ID, row ID is 20 + step + 1.
+	tk.MustExec("insert into tt values(20, 1)")
+	r = tk.MustQuery("admin show tt next_row_id")
+	r.Check(testkit.Rows("test tt id 31"))
+	// test for renaming the table
+	tk.MustExec("create database test1")
+	tk.MustExec("rename table test.tt to test1.tt")
+	tk.MustExec("use test1")
+	r = tk.MustQuery("admin show tt next_row_id")
+	r.Check(testkit.Rows("test1 tt id 31"))
+	tk.MustExec("insert test1.tt values ()")
+	r = tk.MustQuery("admin show tt next_row_id")
+	r.Check(testkit.Rows("test1 tt id 41"))
+}

executor/aggregate_test.go

@@ -239,7 +239,7 @@ func (s *testSuite) TestAggregation(c *C) {
 
 	result = tk.MustQuery("select count(*) from information_schema.columns")
 	// When adding new memory columns in information_schema, please update this variable.
-	columnCountOfAllInformationSchemaTables := "757"
+	columnCountOfAllInformationSchemaTables := "759"
 	result.Check(testkit.Rows(columnCountOfAllInformationSchemaTables))
 
 	tk.MustExec("drop table if exists t1")

executor/builder.go

@@ -112,6 +112,8 @@ func (b *executorBuilder) build(p plannercore.Plan) Executor {
 		return b.buildSelectLock(v)
 	case *plannercore.CancelDDLJobs:
 		return b.buildCancelDDLJobs(v)
+	case *plannercore.ShowNextRowID:
+		return b.buildShowNextRowID(v)
 	case *plannercore.ShowDDL:
 		return b.buildShowDDL(v)
 	case *plannercore.ShowDDLJobs:
@@ -185,6 +187,14 @@ func (b *executorBuilder) buildCancelDDLJobs(v *plannercore.CancelDDLJobs) Execu
 	return e
 }
 
+func (b *executorBuilder) buildShowNextRowID(v *plannercore.ShowNextRowID) Executor {
+	e := &ShowNextRowIDExec{
+		baseExecutor: newBaseExecutor(b.ctx, v.Schema(), v.ExplainID()),
+		tblName:      v.TableName,
+	}
+	return e
+}
+
 func (b *executorBuilder) buildShowDDL(v *plannercore.ShowDDL) Executor {
 	// We get DDLInfo here because for Executors that returns result set,
 	// next will be called after transaction has been committed.

executor/executor.go

@@ -55,6 +55,7 @@ var (
 	_ Executor = &ProjectionExec{}
 	_ Executor = &SelectionExec{}
 	_ Executor = &SelectLockExec{}
+	_ Executor = &ShowNextRowIDExec{}
 	_ Executor = &ShowDDLExec{}
 	_ Executor = &ShowDDLJobsExec{}
 	_ Executor = &ShowDDLJobQueriesExec{}
@@ -200,6 +201,43 @@ func (e *CancelDDLJobsExec) Next(ctx context.Context, chk *chunk.Chunk) error {
 	return nil
 }
 
+// ShowNextRowIDExec represents a show the next row ID executor.
+type ShowNextRowIDExec struct {
+	baseExecutor
+	tblName *ast.TableName
+	done    bool
+}
+
+// Next implements the Executor Next interface.
+func (e *ShowNextRowIDExec) Next(ctx context.Context, chk *chunk.Chunk) error {
+	chk.Reset()
+	if e.done {
+		return nil
+	}
+	is := domain.GetDomain(e.ctx).InfoSchema()
+	tbl, err := is.TableByName(e.tblName.Schema, e.tblName.Name)
+	if err != nil {
+		return errors.Trace(err)
+	}
+	colName := model.ExtraHandleName
+	for _, col := range tbl.Meta().Columns {
+		if mysql.HasAutoIncrementFlag(col.Flag) {
+			colName = col.Name
+			break
+		}
+	}
+	nextGlobalID, err := tbl.Allocator(e.ctx).NextGlobalAutoID(tbl.Meta().ID)
+	if err != nil {
+		return errors.Trace(err)
+	}
+	chk.AppendString(0, e.tblName.Schema.O)
+	chk.AppendString(1, e.tblName.Name.O)
+	chk.AppendString(2, colName.O)
+	chk.AppendInt64(3, nextGlobalID)
+	e.done = true
+	return nil
+}
+
 // ShowDDLExec represents a show DDL executor.
 type ShowDDLExec struct {
 	baseExecutor

parser/misc.go

@@ -355,6 +355,7 @@ var tokenMap = map[string]int{
 	"NAMES":                    names,
 	"NATIONAL":                 national,
 	"NATURAL":                  natural,
+	"NEXT_ROW_ID":              nextRowID,
 	"NO":                       no,
 	"NO_WRITE_TO_BINLOG":       noWriteToBinLog,
 	"NONE":                     none,

parser/parser.y

@@ -420,6 +420,7 @@ import (
 	extract			"EXTRACT"
 	getFormat		"GET_FORMAT"
 	groupConcat		"GROUP_CONCAT"
+	nextRowID		"NEXT_ROW_ID"
 	inplace 		"INPLACE"
 	internal		"INTERNAL"
 	min			"MIN"
@@ -2838,7 +2839,7 @@ TiDBKeyword:
 
 NotKeywordToken:
  "ADDDATE" | "BIT_AND" | "BIT_OR" | "BIT_XOR" | "CAST" | "COPY" | "COUNT" | "CURTIME" | "DATE_ADD" | "DATE_SUB" | "EXTRACT" | "GET_FORMAT" | "GROUP_CONCAT" | "INPLACE" | "INTERNAL" 
-|"MIN" | "MAX" | "MAX_EXECUTION_TIME" | "NOW" | "RECENT" | "POSITION" | "SUBDATE" | "SUBSTRING" | "SUM" | "TIMESTAMPADD" | "TIMESTAMPDIFF" | "TOP" | "TRIM"
+|"MIN" | "MAX" | "MAX_EXECUTION_TIME" | "NOW" | "RECENT" | "POSITION" | "SUBDATE" | "SUBSTRING" | "SUM" | "TIMESTAMPADD" | "TIMESTAMPDIFF" | "TOP" | "TRIM" | "NEXT_ROW_ID"
 
 /************************************************************************************
  *
@@ -5173,6 +5174,13 @@ AdminStmt:
 		    JobNumber: $5.(int64),
 		}
 	}
+|	"ADMIN" "SHOW" TableName "NEXT_ROW_ID"
+	{
+		$$ = &ast.AdminStmt{
+			Tp: ast.AdminShowNextRowID,
+			Tables: []*ast.TableName{$3.(*ast.TableName)},
+		}
+	}
 |	"ADMIN" "CHECK" "TABLE" TableNameList
 	{
 		$$ = &ast.AdminStmt{

parser/parser_test.go

@@ -439,6 +439,7 @@ func (s *testParserSuite) TestDMLStmt(c *C) {
 		{"admin checksum table t1, t2;", true},
 		{"admin cancel ddl jobs 1", true},
 		{"admin cancel ddl jobs 1, 2", true},
+		{"admin show t1 next_row_id", true},
 		{"admin recover index t1 idx_a", true},
 		{"admin cleanup index t1 idx_a", true},
 		{"admin show slow top 3", true},

planner/core/common_plans.go

@@ -60,6 +60,12 @@ type ShowDDLJobQueries struct {
 	JobIDs []int64
 }
 
+// ShowNextRowID is for showing the next global row ID.
+type ShowNextRowID struct {
+	baseSchemaProducer
+	TableName *ast.TableName
+}
+
 // CheckTable is used for checking table data, built from the 'admin check table' statement.
 type CheckTable struct {
 	baseSchemaProducer

planner/core/planbuilder.go

@@ -476,6 +476,10 @@ func (b *planBuilder) buildAdmin(as *ast.AdminStmt) (Plan, error) {
 		p := &ChecksumTable{Tables: as.Tables}
 		p.SetSchema(buildChecksumTableSchema())
 		ret = p
+	case ast.AdminShowNextRowID:
+		p := &ShowNextRowID{TableName: as.Tables[0]}
+		p.SetSchema(buildShowNextRowID())
+		ret = p
 	case ast.AdminShowDDL:
 		p := &ShowDDL{}
 		p.SetSchema(buildShowDDLFields())
@@ -706,6 +710,15 @@ func (b *planBuilder) buildAnalyze(as *ast.AnalyzeTableStmt) (Plan, error) {
 	return b.buildAnalyzeTable(as), nil
 }
 
+func buildShowNextRowID() *expression.Schema {
+	schema := expression.NewSchema(make([]*expression.Column, 0, 4)...)
+	schema.Append(buildColumn("", "DB_NAME", mysql.TypeVarchar, mysql.MaxDatabaseNameLength))
+	schema.Append(buildColumn("", "TABLE_NAME", mysql.TypeVarchar, mysql.MaxTableNameLength))
+	schema.Append(buildColumn("", "COLUMN_NAME", mysql.TypeVarchar, mysql.MaxColumnNameLength))
+	schema.Append(buildColumn("", "NEXT_GLOBAL_ROW_ID", mysql.TypeLonglong, 4))
+	return schema
+}
+
 func buildShowDDLFields() *expression.Schema {
 	schema := expression.NewSchema(make([]*expression.Column, 0, 4)...)
 	schema.Append(buildColumn("", "SCHEMA_VER", mysql.TypeLonglong, 4))