FEDERATED 存储引擎允许您在不使用复制或集群技术的情况下访问远程 MySQL 数据库的数据。查询本地 FEDERATED 表会自动从远程（联邦）表中获取数据。本地表不存储任何数据。The FEDERATED storage engine lets you access data from a remote MySQL database without using replication or cluster technology. Querying a local FEDERATED table automatically pulls the data from the remote (federated) tables. No data is stored on the local tables.

如果从源码构建 MySQL 时要包含 FEDERATED 存储引擎，请使用 CMake 并添加 -DWITH_FEDERATED_STORAGE_ENGINE 选项。To include the FEDERATED storage engine if you build MySQL from source, invoke CMake with the -DWITH_FEDERATED_STORAGE_ENGINE option.

FEDERATED 存储引擎在运行中的服务器中默认未启用；要启用 FEDERATED，必须使用 --federated 选项启动 MySQL 服务器二进制文件。The FEDERATED storage engine is not enabled by default in the running server; to enable FEDERATED, you must start the MySQL server binary using the --federated option.

要查看 FEDERATED 引擎的源代码，请到 MySQL 源码分发包的 storage/federated 目录下查看。To examine the source for the FEDERATED engine, look in the storage/federated directory of a MySQL source distribution.