"David G. Johnston" <david.g.johnston@gmail.com> writes:
> My main point here is that writing "CREATE TYPE typename AS DOMAIN" would
> be expected, with the appropriate sub-specification, similar to "CREATE
> TYPE typename AS RANGE".
Well, that point seems entirely invented. CREATE DOMAIN is in the
SQL standard:
<domain definition> ::=
CREATE DOMAIN <domain name> [ AS ] <predefined type>
[ <default clause> ]
[ <domain constraint>... ]
[ <collate clause> ]
While SQL does also have a CREATE TYPE command, domains are not
among the kinds of type it can make. So that separation is
very much per spec.
I don't personally find the doc changes proposed here to be a good idea.
001 seems to add a lot of verbosity and not much else. 002 invents terms
used nowhere else in our docs, which seems more confusing than anything
else. It is very badly in need of copy-editing, as well.
Also, I think the phrase you are looking for might be "type category".
Using "type definition" to mean that seems completely wrong. Deciding
that capitalized Type means something special is something I might expect
to find in one of the more abstruse philosophers, but it's not a great
idea in the Postgres manual ... especially when you then use different
terminology elsewhere.
regards, tom lane