Re: Sequences and inheritance

On Tue, 31 Jul 2001, Bruce Richardson wrote:

> If I have a set of tables and I set their primary keys all to the same
> sequence, as in
>
> create sequence common_seq;
>
> create table alpha (
> ID integer primary key default nextval('common_seq),
> other_field text
> );
>
> create table beta (
> ID integer primary key default nextval('common_seq),
> other_field real
> );
> create table gamma (
> ID integer primary key default nextval('common_seq),
> other_field oid
> );
>
> Would this guarantee that each value of ID in any row of any of the
> tables would be unique amongst all of them?
yes

> Would I get the same effect by creating a table like this:
>
> create table common (
> ID serial primary key
> );
>
> and then having alpha, beta and gamma inherit from it?
>
no. Primary key constraints are currently not inherited. See the todo-list
for more details.

- Einar Karttunen