On Jul 27, 2005, at 4:49 AM, Tino Wildenhain wrote:
> I'd create a sequence:
>
> CREATE SEQUENCE global_unique_id_seq;
>
> and a function:
>
> CREATE OR REPLACE FUNCTION newid()
> RETURNS text AS
> $BODY$ SELECT nextval('global_unique_id_seq')::text; $BODY$
> LANGUAGE 'sql' VOLATILE;
>
>
> now every call to newid() returns a garantied unique id for
> say the next 18446744073709551616 calls.
> Of course you can obfuscate the ID even more using
> md5, include servername and so on, but this will not improve
> security in any way (unless you mix data with 2nd database)
This is not really a viable replacement for a GUID == globally unique
identifier. Here global means that if I use the application in
multiple databases, I'm guaranteed that no two identifiers will be
the same. Using a sequence will only support uniqueness for a single
database.
Best,
John DeSoi, Ph.D.
http://pgedit.com/
Power Tools for PostgreSQL
