Method renameTable

src/Databases/DatabaseReplicated.cpp:2238–2312

}

void DatabaseReplicated::renameTable(ContextPtr local_context, const String & table_name, IDatabase & to_database,
                                     const String & to_table_name, bool exchange, bool dictionary)
{
    auto txn = local_context->getZooKeeperMetadataTransaction();
    chassert(txn);

    if (this != &to_database)
        throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Moving tables between databases is not supported for Replicated engine");
    if (table_name == to_table_name)
        throw Exception(ErrorCodes::INCORRECT_QUERY, "Cannot rename table to itself");
    if (!isTableExist(table_name, local_context))
        throw Exception(ErrorCodes::UNKNOWN_TABLE, "Table {} does not exist", table_name);
    if (exchange && !to_database.isTableExist(to_table_name, local_context))
        throw Exception(ErrorCodes::UNKNOWN_TABLE, "Table {} does not exist", to_table_name);

    waitDatabaseStarted();

    std::lock_guard lock{metadata_mutex};

    String statement = readMetadataFile(table_name);
    String statement_to;
    if (exchange)
        statement_to = readMetadataFile(to_table_name);

    if (txn->isInitialQuery())
    {
        String metadata_zk_path = zookeeper_path + "/metadata/" + escapeForFileName(table_name);
        String metadata_zk_path_to = zookeeper_path + "/metadata/" + escapeForFileName(to_table_name);

        String zk_statement;
        Coordination::Stat stat;
        String zk_statement_to;
        Coordination::Stat stat_to;

        /// When performing an ALTER operation on ReplicatedMergeTree tables,
        ///  we update the metadata in ZooKeeper before updating it locally.
        /// To prevent overwriting the new version of the metadata, we fetch and
        ///  use the latest version and ensure it hasn't changed using a version check.
        auto zookeeper = txn->getZooKeeper();
        zookeeper->tryGet(metadata_zk_path, zk_statement, &stat);
        zookeeper->tryGet(metadata_zk_path_to, zk_statement_to, &stat_to);

        if (!txn->isCreateOrReplaceQuery())
            txn->addOp(zkutil::makeRemoveRequest(metadata_zk_path, stat.version));

        if (exchange)
        {
            txn->addOp(zkutil::makeRemoveRequest(metadata_zk_path_to, stat_to.version));
            if (!txn->isCreateOrReplaceQuery())
                txn->addOp(zkutil::makeCreateRequest(metadata_zk_path, zk_statement_to, zkutil::CreateMode::Persistent));
        }

        /// In case of CREATE OR REPLACE there is no statement for the temporary table in ZK, so we use the local definition
        if (txn->isCreateOrReplaceQuery())
            txn->addOp(zkutil::makeCreateRequest(metadata_zk_path_to, statement, zkutil::CreateMode::Persistent));
        else
            txn->addOp(zkutil::makeCreateRequest(metadata_zk_path_to, zk_statement, zkutil::CreateMode::Persistent));
    }