Make "NOT NULL" default in Postgresql 9.2 I use NOT NULL a lot when creating columns. 

Is there a way to make this default when defining columns?  In other words, make column is_nullable default to NO. (I realize this would make it harder for me to set it to YES later one.)
YOU have to define NOT NULL when creating a table as described in documentation :

NOT NULL ==>
The column is not allowed to contain null values.

Examples :

CREATE TABLE films (
    code        char(5) CONSTRAINT firstkey PRIMARY KEY,
    title       varchar(40) NOT NULL,
    did         integer NOT NULL,
    date_prod   date,
    kind        varchar(10),
    len         interval hour to minute
);


Define two NOT NULL column constraints on the table distributors, one of which is explicitly given a name:

CREATE TABLE distributors (
    did     integer CONSTRAINT no_null NOT NULL,
    name    varchar(40) NOT NULL
);