Re: Alternative to serial primary key

On 7/6/06, David Clarke <pigwin32(at)gmail(dot)com> wrote:
>
>
> To recap, yes there is only a single column, yes it is varchar. I need
> to do a lookup on the address column which is unique and use it as a
> foreign key in other tables. Using a serial id would obviously work
> and has been recommended. But having a hash function over the address
> column as the primary key means I can always regenerate my primary key
> from the data which is impossible with a serial key. I believe the
> risk of collision using md5 is effectively zero on this data and I can
> put a unique index over it.

So if you have:

addresses
address_id bigserial (pk),
address

person
person_id bigserial (pk),
first_name,
last_name,
address_id

you can do something like

INSERT INTO person (
address_id
)
SELECT
'Joe',
'Blow',
address_id
FROM addresses
WHERE addresses.address = ?;

No regeneration of PK necessary. If you index addresses.address the insert
should run quickly, right?

-Aaron Bono