(PECL memcached >= 0.1.0)
Memcached::deleteByKey — Delete an item from a specific server
Memcached::deleteByKey() is functionally equivalent to Memcached::delete, except that the free-form server_key can be used to map the key to a specific server.
The key identifying the server to delete the item from.
The key to be deleted.
The amount of time the server will wait to delete the item. Defaults to 0.
如果成功则返回 TRUE,失败则返回 FALSE。 The Memcached::getResultCode will return Memcached::RES_NOTFOUND if the key does not exist.