可以调用 show() 方法以查看在当前外部服务器对象（不需要连接到远程）下创建的所有非本机表（永久或临时）的目录。如果将永久非本机表名称传递到 show() 方法，则将显示该非本机表的完整 CREATE TABLE 语句。
scala> s1.show
LINK: s2h.active
+-----------+--------------+------------+
|local_table|remote_table |is_temporary|
+-----------+--------------+------------+
|nn2 |default.test |true |
|default.nn1|user1.players |false |
+-----------+--------------+------------+
scala> s1.show("default.nn1")
+----------------------------------------------------------+
|createtab_stmt |
+----------------------------------------------------------+
|CREATE TABLE `default`.`nn1` (`number` INT, `name` STRING)
USING com.teradata.querygrid.qgc.spark
OPTIONS (
`serialization.format` '1',
`version` 'active',
`link` 's2h',
`table` 'user1.players'
) |
+----------------------------------------------------------+