Alternative Serial

Hi list,

I know that serials must be created like this.

Create the Serial

Create a field table and reffers to the pre-created serial.

Now I noticed that it is possible to use the default value. I am almost quite sure that this is an alternative way and non polite. 

I would like to know if I am correct and what does it means:

nextval('mySerial_id'::regclass)

What is regclass ?

Regards ,
-- 
Ezequias Rodrigues da Rocha
 http://ezequiasrocha.blogspot.com/
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