better rename

src/Databases/DatabaseAtomic.cpp

@@ -121,10 +121,10 @@ void DatabaseAtomic::renameTable(const Context & context, const String & table_n
 
     auto detach = [](DatabaseAtomic & db, const String & table_name_)
     {
-        auto table_data_path_ = db.table_name_to_path.find(table_name_)->second;
+        auto table_data_path_saved = db.table_name_to_path.find(table_name_)->second;
         db.tables.erase(table_name_);
         db.table_name_to_path.erase(table_name_);
-        return table_data_path_;
+        return table_data_path_saved;
     };
 
     auto attach = [](DatabaseAtomic & db, const String & table_name_, const String & table_data_path_, const StoragePtr & table_)
@@ -164,9 +164,9 @@ void DatabaseAtomic::renameTable(const Context & context, const String & table_n
     if (exchange)
         other_table_data_path = detach(other_db, to_table_name);
 
-    table->renameInMemory(other_db.getDatabaseName(), to_table_name);
+    table->renameInMemory({other_db.getDatabaseName(), to_table_name, table->getStorageID().uuid});
     if (exchange)
-        other_table->renameInMemory(getDatabaseName(), table_name);
+        other_table->renameInMemory({getDatabaseName(), table_name, other_table->getStorageID().uuid});
 
     if (!inside_database)
     {

src/Databases/DatabaseOnDisk.cpp

@@ -57,7 +57,7 @@ std::pair<String, StoragePtr> createTableFromAST(
         const auto & table_function = ast_create_query.as_table_function->as<ASTFunction &>();
         const auto & factory = TableFunctionFactory::instance();
         StoragePtr storage = factory.get(table_function.name, context)->execute(ast_create_query.as_table_function, context, ast_create_query.table);
-        storage->resetStorageID({ast_create_query.database, ast_create_query.table, ast_create_query.uuid});
+        storage->renameInMemory(ast_create_query);
         return {ast_create_query.table, storage};
     }
     /// We do not directly use `InterpreterCreateQuery::execute`, because
@@ -285,8 +285,7 @@ void DatabaseOnDisk::renameTable(
             create.uuid = UUIDHelpers::Nil;
 
         /// Notify the table that it is renamed. It will move data to new path (if it stores data on disk) and update StorageID
-        table->rename(to_database.getTableDataPath(create), to_database.getDatabaseName(), to_table_name, table_lock);
-        table->resetStorageID({create.database, create.table, create.uuid});  /// reset UUID
+        table->rename(to_database.getTableDataPath(create), StorageID(create));
     }
     catch (const Exception &)
     {

src/Interpreters/DDLWorker.cpp

@@ -638,7 +638,7 @@ void DDLWorker::processTask(DDLTask & task, const ZooKeeperPtr & zookeeper)
                 if (!query_with_table->table.empty())
                 {
                     /// It's not CREATE DATABASE
-                    auto table_id = context.resolveStorageID(*query_with_table, Context::ResolveOrdinary);
+                    auto table_id = context.tryResolveStorageID(*query_with_table, Context::ResolveOrdinary);
                     storage = DatabaseCatalog::instance().tryGetTable(table_id);
                 }
 

src/Interpreters/InterpreterCreateQuery.cpp

@@ -647,7 +647,7 @@ bool InterpreterCreateQuery::doCreateTable(ASTCreateQuery & create,
         const auto & table_function = create.as_table_function->as<ASTFunction &>();
         const auto & factory = TableFunctionFactory::instance();
         res = factory.get(table_function.name, context)->execute(create.as_table_function, context, create.table);
-        res->resetStorageID({create.database, create.table, create.uuid});
+        res->renameInMemory({create.database, create.table, create.uuid});
     }
     else
     {

src/Interpreters/InterpreterShowCreateQuery.cpp

@@ -14,6 +14,7 @@
 #include <Interpreters/Context.h>
 #include <Interpreters/InterpreterShowCreateQuery.h>
 
+#include <Parsers/ASTCreateQuery.h>
 
 namespace DB
 {
@@ -72,6 +73,10 @@ BlockInputStreamPtr InterpreterShowCreateQuery::executeImpl()
     if (!create_query && show_query && show_query->temporary)
         throw Exception("Unable to show the create query of " + show_query->table + ". Maybe it was created by the system.", ErrorCodes::THERE_IS_NO_QUERY);
 
+    //FIXME temporary print create query without UUID for tests (remove it)
+    auto & create = create_query->as<ASTCreateQuery &>();
+    create.uuid = UUIDHelpers::Nil;
+
     std::stringstream stream;
     formatAST(*create_query, stream, false, true);
     String res = stream.str();

src/Interpreters/StorageID.cpp

@@ -33,9 +33,7 @@ StorageID::StorageID(const ASTIdentifier & table_identifier_node)
 
 StorageID::StorageID(const ASTPtr & node)
 {
-    if (!node)
-        *this = StorageID();
-    else if (auto identifier = dynamic_cast<const ASTIdentifier *>(node.get()))
+    if (auto identifier = dynamic_cast<const ASTIdentifier *>(node.get()))
         *this = StorageID(*identifier);
     else if (auto simple_query = dynamic_cast<const ASTQueryWithTableAndOutput *>(node.get()))
         *this = StorageID(*simple_query);

src/Parsers/ASTIdentifier.cpp

@@ -13,6 +13,7 @@ namespace DB
 namespace ErrorCodes
 {
     extern const int UNEXPECTED_AST_STRUCTURE;
+    extern const int SYNTAX_ERROR;
 }
 
 
@@ -163,4 +164,17 @@ void setIdentifierSpecial(ASTPtr & ast)
             id->semantic->special = true;
 }
 
+StorageID getTableIdentifier(const ASTPtr & ast)
+{
+    if (!ast)
+        throw Exception("AST node is nullptr", ErrorCodes::UNEXPECTED_AST_STRUCTURE);
+    const auto & identifier = dynamic_cast<const ASTIdentifier &>(*ast);
+    if (identifier.name_parts.size() > 2)
+        throw Exception("Logical error: more than two components in table expression", ErrorCodes::SYNTAX_ERROR);
+
+    if (identifier.name_parts.size() == 2)
+        return { identifier.name_parts[0], identifier.name_parts[1], identifier.uuid };
+    return { "", identifier.name, identifier.uuid };
+}
+
 }

src/Parsers/ASTIdentifier.h

@@ -66,6 +66,7 @@ private:
     friend struct IdentifierSemantic;
     friend ASTPtr createTableIdentifier(const StorageID & table_id);
     friend void setIdentifierSpecial(ASTPtr & ast);
+    friend StorageID getTableIdentifier(const ASTPtr & ast);
 };
 
 
@@ -78,6 +79,7 @@ void setIdentifierSpecial(ASTPtr & ast);
 String getIdentifierName(const IAST * ast);
 std::optional<String> tryGetIdentifierName(const IAST * ast);
 bool tryGetIdentifierNameInto(const IAST * ast, String & name);
+StorageID getTableIdentifier(const ASTPtr & ast);
 
 inline String getIdentifierName(const ASTPtr & ast) { return getIdentifierName(ast.get()); }
 inline std::optional<String> tryGetIdentifierName(const ASTPtr & ast) { return tryGetIdentifierName(ast.get()); }

src/Parsers/ExpressionElementParsers.cpp

@@ -194,7 +194,7 @@ bool ParserCompoundIdentifier::parseImpl(Pos & pos, ASTPtr & node, Expected & ex
     ParserKeyword s_uuid("UUID");
     UUID uuid = UUIDHelpers::Nil;
 
-    if (allow_uuid && s_uuid.ignore(pos, expected))
+    if (table_name_with_optional_uuid && parts.size() <= 2 && s_uuid.ignore(pos, expected))
     {
         ParserStringLiteral uuid_p;
         ASTPtr ast_uuid;

src/Parsers/ExpressionElementParsers.h

@@ -61,11 +61,12 @@ protected:
 class ParserCompoundIdentifier : public IParserBase
 {
 public:
-    ParserCompoundIdentifier(bool allow_uuid_ = false) : allow_uuid(allow_uuid_) {}
+    ParserCompoundIdentifier(bool table_name_with_optional_uuid_ = false)
+    : table_name_with_optional_uuid(table_name_with_optional_uuid_) {}
 protected:
     const char * getName() const override { return "compound identifier"; }
     bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override;
-    bool allow_uuid;
+    bool table_name_with_optional_uuid;
 };
 
 /// Just *

src/Parsers/ParserCreateQuery.cpp

@@ -391,7 +391,7 @@ bool ParserCreateTableQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expe
             return false;
     }
 
-    StorageID table_id{table};
+    StorageID table_id = getTableIdentifier(table);
 
     // Shortcut for ATTACH a previously detached table
     if (attach && (!pos.isValid() || pos.get().type == TokenType::Semicolon))
@@ -571,13 +571,14 @@ bool ParserCreateLiveViewQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & e
     query->if_not_exists = if_not_exists;
     query->is_live_view = true;
 
-    StorageID table_id{table};
+    StorageID table_id = getTableIdentifier(table);
     query->database = table_id.database_name;
     query->table = table_id.table_name;
     query->uuid = table_id.uuid;
     query->cluster = cluster_str;
 
-    query->to_table_id = StorageID(to_table);
+    if (to_table)
+        query->to_table_id = getTableIdentifier(to_table);
 
     query->set(query->columns_list, columns_list);
 
@@ -764,13 +765,14 @@ bool ParserCreateViewQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expec
     query->is_populate = is_populate;
     query->replace_view = replace_view;
 
-    StorageID table_id{table};
+    StorageID table_id = getTableIdentifier(table);
     query->database = table_id.database_name;
     query->table = table_id.table_name;
     query->uuid = table_id.uuid;
     query->cluster = cluster_str;
 
-    query->to_table_id = StorageID(to_table);
+    if (to_table)
+        query->to_table_id = getTableIdentifier(to_table);
 
     query->set(query->columns_list, columns_list);
     query->set(query->storage, storage);

src/Storages/IStorage.cpp

@@ -416,17 +416,10 @@ StorageID IStorage::getStorageID() const
     return storage_id;
 }
 
-void IStorage::renameInMemory(const String & new_database_name, const String & new_table_name)
+void IStorage::renameInMemory(const StorageID & new_table_id)
 {
     std::lock_guard lock(id_mutex);
-    storage_id.database_name = new_database_name;
-    storage_id.table_name = new_table_name;
-}
-
-void IStorage::resetStorageID(const StorageID & actual_table_id)
-{
-    std::lock_guard lock(id_mutex);
-    storage_id = actual_table_id;
+    storage_id = new_table_id;
 }
 
 }

src/Storages/IStorage.h

@@ -95,11 +95,6 @@ public:
     /// The name of the table.
     StorageID getStorageID() const;
 
-    /// This method is required to set actual storage id for storage created by table function.
-    /// Also it's required for moving table between Ordinary and Atomic databases. Do not use it for other purposes.
-    /// TODO refactor table names in table functions
-    void resetStorageID(const StorageID & actual_table_id);
-
     /// Returns true if the storage receives data from a remote server or servers.
     virtual bool isRemote() const { return false; }
 
@@ -328,18 +323,18 @@ public:
       * Renaming a name in a file with metadata, the name in the list of tables in the RAM, is done separately.
       * In this function, you need to rename the directory with the data, if any.
       * Called when the table structure is locked for write.
+      * Table UUID must remain unchanged, unless table moved between Ordinary and Atomic databases.
       */
-    virtual void rename(const String & /*new_path_to_table_data*/, const String & new_database_name, const String & new_table_name,
-                        TableStructureWriteLockHolder &)
+    virtual void rename(const String & /*new_path_to_table_data*/, const StorageID & new_table_id)
     {
-        renameInMemory(new_database_name, new_table_name);
+        renameInMemory(new_table_id);
     }
 
     /**
      * Just updates names of database and table without moving any data on disk
      * Can be called directly only from DatabaseAtomic.
      */
-    virtual void renameInMemory(const String & new_database_name, const String & new_table_name);
+    virtual void renameInMemory(const StorageID & new_table_id);
 
     /** ALTER tables in the form of column changes that do not affect the change to Storage or its parameters.
       * This method must fully execute the ALTER query, taking care of the locks itself.

src/Storages/MergeTree/MergeTreeData.cpp

@@ -1298,9 +1298,7 @@ void MergeTreeData::clearPartsFromFilesystem(const DataPartsVector & parts_to_re
     }
 }
 
-void MergeTreeData::rename(
-    const String & new_table_path, const String & new_database_name,
-    const String & new_table_name, TableStructureWriteLockHolder &)
+void MergeTreeData::rename(const String & new_table_path, const StorageID & new_table_id)
 {
     auto disks = getStoragePolicy()->getDisks();
 
@@ -1320,7 +1318,7 @@ void MergeTreeData::rename(
     global_context.dropCaches();
 
     relative_data_path = new_table_path;
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 void MergeTreeData::dropAllData()

src/Storages/MergeTree/MergeTreeData.h

@@ -511,8 +511,7 @@ public:
     /// Moves the entire data directory.
     /// Flushes the uncompressed blocks cache and the marks cache.
     /// Must be called with locked lockStructureForAlter().
-    void rename(const String & new_table_path, const String & new_database_name,
-        const String & new_table_name, TableStructureWriteLockHolder &) override;
+    void rename(const String & new_table_path, const StorageID & new_table_id) override;
 
     /// Check if the ALTER can be performed:
     /// - all needed columns are present.

src/Storages/StorageDistributed.cpp

@@ -717,12 +717,11 @@ void StorageDistributed::flushClusterNodesAllData()
         node.second.flushAllData();
 }
 
-void StorageDistributed::rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name,
-                                TableStructureWriteLockHolder &)
+void StorageDistributed::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     if (!relative_data_path.empty())
         renameOnDisk(new_path_to_table_data);
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 void StorageDistributed::renameOnDisk(const String & new_path_to_table_data)
 {

src/Storages/StorageDistributed.h

@@ -82,7 +82,7 @@ public:
     /// Removes temporary data in local filesystem.
     void truncate(const ASTPtr &, const Context &, TableStructureWriteLockHolder &) override;
 
-    void rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
     void renameOnDisk(const String & new_path_to_table_data);
 
     void checkAlterIsPossible(const AlterCommands & commands, const Settings & /* settings */) override;

src/Storages/StorageFile.cpp

@@ -497,7 +497,7 @@ Strings StorageFile::getDataPaths() const
     return paths;
 }
 
-void StorageFile::rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &)
+void StorageFile::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     if (!is_db_table)
         throw Exception("Can't rename table " + getStorageID().getNameForLogs() + " binded to user-defined file (or FD)", ErrorCodes::DATABASE_ACCESS_DENIED);
@@ -512,7 +512,7 @@ void StorageFile::rename(const String & new_path_to_table_data, const String & n
     Poco::File(paths[0]).renameTo(path_new);
 
     paths[0] = std::move(path_new);
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 void StorageFile::truncate(const ASTPtr & /*query*/, const Context & /* context */, TableStructureWriteLockHolder &)

src/Storages/StorageFile.h

@@ -38,7 +38,7 @@ public:
 
     void truncate(const ASTPtr & /*query*/, const Context & /* context */, TableStructureWriteLockHolder &) override;
 
-    void rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     Strings getDataPaths() const override;
 

src/Storages/StorageLog.cpp

@@ -514,7 +514,7 @@ void StorageLog::loadMarks()
 }
 
 
-void StorageLog::rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &)
+void StorageLog::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     std::unique_lock<std::shared_mutex> lock(rwlock);
 
@@ -527,7 +527,7 @@ void StorageLog::rename(const String & new_path_to_table_data, const String & ne
         file.second.data_file_path = table_path + fileName(file.second.data_file_path);
 
     marks_file_path = table_path + DBMS_STORAGE_LOG_MARKS_FILE_NAME;
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 void StorageLog::truncate(const ASTPtr &, const Context &, TableStructureWriteLockHolder &)

src/Storages/StorageLog.h

@@ -34,11 +34,7 @@ public:
 
     BlockOutputStreamPtr write(const ASTPtr & query, const Context & context) override;
 
-    void rename(
-        const String & new_path_to_table_data,
-        const String & new_database_name,
-        const String & new_table_name,
-        TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     CheckResults checkData(const ASTPtr & /* query */, const Context & /* context */) override;
 

src/Storages/StorageMaterializedView.cpp

@@ -327,13 +327,16 @@ void StorageMaterializedView::mutate(const MutationCommands & commands, const Co
     getTargetTable()->mutate(commands, context);
 }
 
-void StorageMaterializedView::renameInMemory(const String & new_database_name, const String & new_table_name)
+void StorageMaterializedView::renameInMemory(const StorageID & new_table_id)
 {
     auto old_table_id = getStorageID();
-    ///FIXME case when moving between DBs
-    if (has_inner_table && tryGetTargetTable() && !old_table_id.hasUUID())
+    auto old_target_table_name = generateInnerTableName(old_table_id);
+    auto new_target_table_name = generateInnerTableName(new_table_id);
+    bool inner_same_name = old_table_id.database_name == new_table_id.database_name &&
+                           old_target_table_name == new_target_table_name;
+
+    if (has_inner_table && tryGetTargetTable() && !inner_same_name)
     {
-        auto new_target_table_name = generateInnerTableName({new_database_name, new_table_name});
         auto rename = std::make_shared<ASTRenameQuery>();
 
         ASTRenameQuery::Table from;
@@ -353,7 +356,7 @@ void StorageMaterializedView::renameInMemory(const String & new_database_name, c
         target_table_id.table_name = new_target_table_name;
     }
 
-    IStorage::renameInMemory(new_database_name, new_table_name);
+    IStorage::renameInMemory(new_table_id);
     // TODO Actually we don't need to update dependency if MV has UUID, but then db and table name will be outdated
     DatabaseCatalog::instance().updateDependency(select_table_id, old_table_id, select_table_id, getStorageID());
 }

src/Storages/StorageMaterializedView.h

@@ -52,7 +52,7 @@ public:
 
     void mutate(const MutationCommands & commands, const Context & context) override;
 
-    void renameInMemory(const String & new_database_name, const String & new_table_name) override;
+    void renameInMemory(const StorageID & new_table_id) override;
 
     void shutdown() override;
 

src/Storages/StorageReplicatedMergeTree.cpp

@@ -3624,11 +3624,9 @@ void StorageReplicatedMergeTree::drop()
 }
 
 
-void StorageReplicatedMergeTree::rename(
-    const String & new_path_to_table_data, const String & new_database_name,
-    const String & new_table_name, TableStructureWriteLockHolder & lock)
+void StorageReplicatedMergeTree::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
-    MergeTreeData::rename(new_path_to_table_data, new_database_name, new_table_name, lock);
+    MergeTreeData::rename(new_path_to_table_data, new_table_id);
 
     /// Update table name in zookeeper
     auto zookeeper = getZooKeeper();

src/Storages/StorageReplicatedMergeTree.h

@@ -117,7 +117,7 @@ public:
 
     void truncate(const ASTPtr &, const Context &, TableStructureWriteLockHolder &) override;
 
-    void rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     bool supportsIndexForIn() const override { return true; }
 

src/Storages/StorageSet.cpp

@@ -197,15 +197,14 @@ void StorageSetOrJoinBase::restoreFromFile(const String & file_path)
 }
 
 
-void StorageSetOrJoinBase::rename(
-    const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &)
+void StorageSetOrJoinBase::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     /// Rename directory with data.
     String new_path = base_path + new_path_to_table_data;
     Poco::File(path).renameTo(new_path);
 
     path = new_path;
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 

src/Storages/StorageSet.h

@@ -19,7 +19,7 @@ class StorageSetOrJoinBase : public IStorage
     friend class SetOrJoinBlockOutputStream;
 
 public:
-    void rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     BlockOutputStreamPtr write(const ASTPtr & query, const Context & context) override;
 

src/Storages/StorageStripeLog.cpp

@@ -237,7 +237,7 @@ StorageStripeLog::StorageStripeLog(
 }
 
 
-void StorageStripeLog::rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &)
+void StorageStripeLog::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     std::unique_lock<std::shared_mutex> lock(rwlock);
 
@@ -245,7 +245,7 @@ void StorageStripeLog::rename(const String & new_path_to_table_data, const Strin
 
     table_path = new_path_to_table_data;
     file_checker.setPath(table_path + "sizes.json");
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 

src/Storages/StorageStripeLog.h

@@ -35,11 +35,7 @@ public:
 
     BlockOutputStreamPtr write(const ASTPtr & query, const Context & context) override;
 
-    void rename(
-        const String & new_path_to_table_data,
-        const String & new_database_name,
-        const String & new_table_name,
-        TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     CheckResults checkData(const ASTPtr & /* query */, const Context & /* context */) override;
 

src/Storages/StorageTinyLog.cpp

@@ -375,7 +375,7 @@ void StorageTinyLog::addFiles(const String & column_name, const IDataType & type
 }
 
 
-void StorageTinyLog::rename(const String & new_path_to_table_data, const String & new_database_name, const String & new_table_name, TableStructureWriteLockHolder &)
+void StorageTinyLog::rename(const String & new_path_to_table_data, const StorageID & new_table_id)
 {
     std::unique_lock<std::shared_mutex> lock(rwlock);
 
@@ -386,7 +386,7 @@ void StorageTinyLog::rename(const String & new_path_to_table_data, const String
 
     for (auto & file : files)
         file.second.data_file_path = table_path + fileName(file.second.data_file_path);
-    renameInMemory(new_database_name, new_table_name);
+    renameInMemory(new_table_id);
 }
 
 

src/Storages/StorageTinyLog.h

@@ -34,11 +34,7 @@ public:
 
     BlockOutputStreamPtr write(const ASTPtr & query, const Context & context) override;
 
-    void rename(
-        const String & new_path_to_table_data,
-        const String & new_database_name,
-        const String & new_table_name,
-        TableStructureWriteLockHolder &) override;
+    void rename(const String & new_path_to_table_data, const StorageID & new_table_id) override;
 
     CheckResults checkData(const ASTPtr & /* query */, const Context & /* context */) override;