no zuo no die系列，来自于pg的wiki。 这是第三部分，包括psql登录时无需带-W/--password参数以及不要使用继承表（inheritance）。 一、psql不带-W 原因是： >Using the --password or -W flags will tell psql to prompt you for a password, before trying to connect to the server - so you'll be prompted for a password even if the server doesn't require one. It's never required, as if the server does require a password psql will prompt you for one, and it can be very confusing when setting up permissions. If you're connecting with -W to a server configured to allow you access via peer authentication you may think that it's requiring a password when it really isn't. And if the user you're logging in as doesn't have a password set or you enter the wrong password at the prompt you'll still be logged in and think you have the right password - but you won't be able to log in from other clients (that connect via localhost) or when logged in as other users. 简单来说就是，不需要密码的，带了该参数，无论输入什么或者不输入都可以登录；而需要密码时，带不带该参数都会提示输入密码。 ``` pg12@localhost ~]$ psql -d testdb -W Password: --> 不输入密码，直接回车也可以登录 Timing is on. Expanded display is used automatically. psql (12.0) Type "help" for help. [local]:5432 pg12@testdb=# ``` 二、不使用继承表 原因是： >Table inheritance was a part of a fad wherein the database was closely coupled to object-oriented code. It turned out that coupling things that closely didn't actually produce the desired results. 继承表的设计目的是为了使用面向对象的设计方法，但对于RDBMS的数据库而非OO数据库，使用继承并没有必要，反而增加复杂度和理解的难度。 **参考资料** [Don't Do This](https://wiki.postgresql.org/wiki/Don't_Do_This)