摘要：
相当于alias，比如把user1.table1 在user2中建一个同义词table1create synonym table1 for user1.table1;这样当我们在user2中查select * from table1 时就相当于查select * from user1.table1; 阅读全文
摘要：
1.Always Use Comments in Scripts2.Make a Scripts exit When Fails Sometimes bash may continue to execute a script even when a certain command fails.thu 阅读全文