Re: Type modifiers for DOMAIN

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Because the domain is supposed to be opaque as to exactly what its
> underlying type is. In particular, you're supposed to do this:
>
> CREATE DOMAIN varchar2 AS pg_catalog.varchar(10);
>
> If you look in the SQL spec you will not find any suggestion that it
> should work the way you propose.

Hmmm, it means we need to create domains for each length of character types.
If we allowed domains with pass-through-modifiers, it could save codes
than CREATE (scalar) TYPE.

=# CREATE DOMAIN digit_varchar AS varchar ( <pass-through-modifiers> )
CHECK (VALUE ~ E'^\\d*$');
=# CREATE TABLE tbl (digit10 digit_varchar(10));

Regards,
---
Takahiro Itagaki
NTT Open Source Software Center