SQL:
1.create database link db1 connect to <用户名> identified by <密码> using <数据库实例名>
2. select a.*,b.*
from table@db1 a
full outer join table b
on a.id=b.id
where a.id is null or b.id is null
参考:http://www.ehow.com/how_7259465_connect-sql-databases-using-sql_plus.html
导出到excel中对比。