Serial type not working on postgres when creating a Domain?

I have run into a strange pr开发者_如何学JAVAoblem with Postgres 9 on Mac OS X, I have the following statement which works on Windows Postgres but on on Mac OS postgres

CREATE DOMAIN pkey_domain AS SERIAL PRIMARY KEY;

returns

ERROR: type "serial" does not exist

*** Error ***

ERROR: type "serial" does not exist SQL state: 42704

SERIAL is a data type that is supported by postgres why am I not able to create a Domain with it? Does the deafult installer on the Mac not create the type?

Serial isn't really a type, it is a kind of macro that creates the sequence for you, sets the default value of the column, etc. It is not referenced in pg_type. So you can't use it like this.