*: some tiny optimizations to reduce infoschema v2 memory

pkg/infoschema/infoschema_v2.go

@@ -178,6 +178,7 @@ func (isd *Data) addSpecialDB(di *model.DBInfo, tables *schemaTables) {
 }
 
 func (isd *Data) addDB(schemaVersion int64, dbInfo *model.DBInfo) {
+	dbInfo.Tables = nil
 	isd.schemaMap.Set(schemaItem{schemaVersion: schemaVersion, dbInfo: dbInfo})
 }
 
@@ -311,6 +312,10 @@ func (is *infoschemaV2) CloneAndUpdateTS(startTS uint64) *infoschemaV2 {
 }
 
 func (is *infoschemaV2) TableByID(id int64) (val table.Table, ok bool) {
+	return is.tableByID(id, false)
+}
+
+func (is *infoschemaV2) tableByID(id int64, noRefill bool) (val table.Table, ok bool) {
 	if !tableIDIsValid(id) {
 		return
 	}
@@ -340,7 +345,9 @@ func (is *infoschemaV2) TableByID(id int64) (val table.Table, ok bool) {
 	oldKey := tableCacheKey{itm.tableID, itm.schemaVersion}
 	tbl, found = is.tableCache.Get(oldKey)
 	if found && tbl != nil {
-		is.tableCache.Set(key, tbl)
+		if !noRefill {
+			is.tableCache.Set(key, tbl)
+		}
 		return tbl, true
 	}
 
@@ -350,7 +357,9 @@ func (is *infoschemaV2) TableByID(id int64) (val table.Table, ok bool) {
 		return nil, false
 	}
 
-	is.tableCache.Set(key, ret)
+	if !noRefill {
+		is.tableCache.Set(key, ret)
+	}
 	return ret, true
 }
 
@@ -415,7 +424,33 @@ func (is *infoschemaV2) TableInfoByID(id int64) (*model.TableInfo, bool) {
 
 // SchemaTableInfos implements InfoSchema.FindTableInfoByPartitionID
 func (is *infoschemaV2) SchemaTableInfos(schema model.CIStr) []*model.TableInfo {
-	return getTableInfoList(is.SchemaTables(schema))
+	if isSpecialDB(schema.L) {
+		schTbls := is.Data.specials[schema.L]
+		tables := make([]table.Table, 0, len(schTbls.tables))
+		for _, tbl := range schTbls.tables {
+			tables = append(tables, tbl)
+		}
+		return getTableInfoList(tables)
+	}
+
+	dbInfo, ok := is.SchemaByName(schema)
+	if !ok {
+		return nil
+	}
+	snapshot := is.r.Store().GetSnapshot(kv.NewVersion(is.ts))
+	// Using the KV timeout read feature to address the issue of potential DDL lease expiration when
+	// the meta region leader is slow.
+	snapshot.SetOption(kv.TiKVClientReadTimeout, uint64(3000)) // 3000ms.
+	m := meta.NewSnapshotMeta(snapshot)
+	tblInfos, err := m.ListTables(dbInfo.ID)
+	if err != nil {
+		if meta.ErrDBNotExists.Equal(err) {
+			return nil
+		}
+		// TODO: error could happen, so do not panic!
+		panic(err)
+	}
+	return tblInfos
 }
 
 // FindTableInfoByPartitionID implements InfoSchema.FindTableInfoByPartitionID
@@ -611,7 +646,7 @@ retry:
 	}
 	tables = make([]table.Table, 0, len(tblInfos))
 	for _, tblInfo := range tblInfos {
-		tbl, ok := is.TableByID(tblInfo.ID)
+		tbl, ok := is.tableByID(tblInfo.ID, true)
 		if !ok {
 			// what happen?
 			continue
@@ -912,8 +947,8 @@ func (b *bundleInfoBuilder) updateInfoSchemaBundlesV2(is *infoschemaV2) {
 	// TODO: This is quite inefficient! we need some better way or avoid this API.
 	is.ruleBundleMap = make(map[int64]*placement.Bundle)
 	for _, dbInfo := range is.AllSchemas() {
-		for _, tbl := range is.SchemaTables(dbInfo.Name) {
-			b.updateTableBundles(is, tbl.Meta().ID)
+		for _, tbl := range is.SchemaTableInfos(dbInfo.Name) {
+			b.updateTableBundles(is, tbl.ID)
 		}
 	}
 }

pkg/infoschema/infoschema_v2_test.go

@@ -39,6 +39,7 @@ func TestV2Basic(t *testing.T) {
 	is.Data.addDB(1, dbInfo)
 	internal.AddDB(t, r.Store(), dbInfo)
 	tblInfo := internal.MockTableInfo(t, r.Store(), tableName.O)
+	tblInfo.DBID = dbInfo.ID
 	is.Data.add(tableItem{schemaName.L, dbInfo.ID, tableName.L, tblInfo.ID, 2, false}, internal.MockTable(t, r.Store(), tblInfo))
 	internal.AddTable(t, r.Store(), dbInfo, tblInfo)
 	is.base().schemaMetaVersion = 1
@@ -102,7 +103,7 @@ func TestV2Basic(t *testing.T) {
 
 	tblInfos := is.SchemaTableInfos(schemaName)
 	require.Equal(t, 1, len(tblInfos))
-	require.Same(t, tables[0].Meta(), tblInfos[0])
+	require.Equal(t, tables[0].Meta(), tblInfos[0])
 
 	tables = is.SchemaTables(model.NewCIStr("notexist"))
 	require.Equal(t, 0, len(tables))

pkg/server/handler/tests/http_handler_test.go

@@ -1130,7 +1130,7 @@ func TestWriteDBTablesData(t *testing.T) {
 	// No table in a schema.
 	info := infoschema.MockInfoSchema([]*model.TableInfo{})
 	rc := httptest.NewRecorder()
-	tbs := info.SchemaTables(model.NewCIStr("test"))
+	tbs := info.SchemaTableInfos(model.NewCIStr("test"))
 	require.Equal(t, 0, len(tbs))
 	tikvhandler.WriteDBTablesData(rc, tbs)
 	var ti []*model.TableInfo
@@ -1142,30 +1142,30 @@ func TestWriteDBTablesData(t *testing.T) {
 	// One table in a schema.
 	info = infoschema.MockInfoSchema([]*model.TableInfo{core.MockSignedTable()})
 	rc = httptest.NewRecorder()
-	tbs = info.SchemaTables(model.NewCIStr("test"))
+	tbs = info.SchemaTableInfos(model.NewCIStr("test"))
 	require.Equal(t, 1, len(tbs))
 	tikvhandler.WriteDBTablesData(rc, tbs)
 	decoder = json.NewDecoder(rc.Body)
 	err = decoder.Decode(&ti)
 	require.NoError(t, err)
 	require.Equal(t, 1, len(ti))
-	require.Equal(t, ti[0].ID, tbs[0].Meta().ID)
-	require.Equal(t, ti[0].Name.String(), tbs[0].Meta().Name.String())
+	require.Equal(t, ti[0].ID, tbs[0].ID)
+	require.Equal(t, ti[0].Name.String(), tbs[0].Name.String())
 
 	// Two tables in a schema.
 	info = infoschema.MockInfoSchema([]*model.TableInfo{core.MockSignedTable(), core.MockUnsignedTable()})
 	rc = httptest.NewRecorder()
-	tbs = info.SchemaTables(model.NewCIStr("test"))
+	tbs = info.SchemaTableInfos(model.NewCIStr("test"))
 	require.Equal(t, 2, len(tbs))
 	tikvhandler.WriteDBTablesData(rc, tbs)
 	decoder = json.NewDecoder(rc.Body)
 	err = decoder.Decode(&ti)
 	require.NoError(t, err)
 	require.Equal(t, 2, len(ti))
-	require.Equal(t, ti[0].ID, tbs[0].Meta().ID)
-	require.Equal(t, ti[1].ID, tbs[1].Meta().ID)
-	require.Equal(t, ti[0].Name.String(), tbs[0].Meta().Name.String())
-	require.Equal(t, ti[1].Name.String(), tbs[1].Meta().Name.String())
+	require.Equal(t, ti[0].ID, tbs[0].ID)
+	require.Equal(t, ti[1].ID, tbs[1].ID)
+	require.Equal(t, ti[0].Name.String(), tbs[0].Name.String())
+	require.Equal(t, ti[1].Name.String(), tbs[1].Name.String())
 }
 
 func TestSetLabels(t *testing.T) {

pkg/server/handler/tikvhandler/tikv_handler.go

@@ -922,7 +922,7 @@ func (h SchemaStorageHandler) ServeHTTP(w http.ResponseWriter, req *http.Request
 // For every table in the input, we marshal them. The result such as {tb1} {tb2} {tb3}.
 // Then we add some bytes to make it become [{tb1}, {tb2}, {tb3}], so we can unmarshal it to []*model.TableInfo.
 // Note: It would return StatusOK even if errors occur. But if errors occur, there must be some bugs.
-func WriteDBTablesData(w http.ResponseWriter, tbs []table.Table) {
+func WriteDBTablesData(w http.ResponseWriter, tbs []*model.TableInfo) {
 	if len(tbs) == 0 {
 		handler.WriteData(w, []*model.TableInfo{})
 		return
@@ -946,7 +946,7 @@ func WriteDBTablesData(w http.ResponseWriter, tbs []table.Table) {
 		} else {
 			init = true
 		}
-		js, err := json.MarshalIndent(tb.Meta(), "", " ")
+		js, err := json.MarshalIndent(tb, "", " ")
 		if err != nil {
 			terror.Log(errors.Trace(err))
 			return
@@ -987,7 +987,7 @@ func (h SchemaHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		}
 		// all table schemas in a specified database
 		if schema.SchemaExists(cDBName) {
-			tbs := schema.SchemaTables(cDBName)
+			tbs := schema.SchemaTableInfos(cDBName)
 			WriteDBTablesData(w, tbs)
 			return
 		}
@@ -1016,7 +1016,7 @@ func (h SchemaHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			handler.WriteError(w, infoschema.ErrTableNotExists.GenWithStack("Table which ID = %s does not exist.", tableID))
 			return
 		}
-		handler.WriteData(w, tbl.Meta())
+		handler.WriteData(w, tbl)
 		return
 	}
 

pkg/statistics/handle/util/table_info.go

@@ -60,9 +60,8 @@ func (c *tableInfoGetterImpl) TableInfoByID(is infoschema.InfoSchema, physicalID
 func buildPartitionID2TableID(is infoschema.InfoSchema) map[int64]int64 {
 	mapper := make(map[int64]int64)
 	for _, dbName := range is.AllSchemaNames() {
-		tbls := is.SchemaTables(dbName)
+		tbls := is.SchemaTableInfos(dbName)
 		for _, tbl := range tbls {
-			tbl := tbl.Meta()
 			pi := tbl.GetPartitionInfo()
 			if pi == nil {
 				continue

pkg/ttl/cache/infoschema.go

@@ -50,8 +50,7 @@ func (isc *InfoSchemaCache) Update(se session.Session) error {
 
 	newTables := make(map[int64]*PhysicalTable, len(isc.Tables))
 	for _, dbName := range is.AllSchemaNames() {
-		for _, tbl := range is.SchemaTables(dbName) {
-			tblInfo := tbl.Meta()
+		for _, tblInfo := range is.SchemaTableInfos(dbName) {
 			if tblInfo.TTLInfo == nil || !tblInfo.TTLInfo.Enable || tblInfo.State != model.StatePublic {
 				continue
 			}

pkg/ttl/ttlworker/job_manager.go

@@ -1064,8 +1064,7 @@ GROUP BY
 
 	noRecordTables := make([]string, 0)
 	for _, dbName := range is.AllSchemaNames() {
-		for _, tbl := range is.SchemaTables(dbName) {
-			tblInfo := tbl.Meta()
+		for _, tblInfo := range is.SchemaTableInfos(dbName) {
 			if tblInfo.TTLInfo == nil {
 				continue
 			}