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