Re: postgres adapater problem with create_table :id => false

Howard Yeh
Thu, 17 Sep 2009 23:42:27 -0000

On Sep 17, 2:13 pm, Marnen Laibow-Koser <rails-mailing-l...@andreas-
s.net> wrote:
> Howard Yeh wrote:
>
> [...]
>
> > The particular case is for a has_many association, but I want to avoid
> > the overhead of having two indices.
>
> That strikes me as a foolish premature optimization, rather like saying
> that you don''t want headlights on your car because they take too
much
> power from the engine. :)
>
>
>
> > It''ll be insertion only, so duplicate foreign key is
acceptable.
>
> Well, of course duplicate foreign keys would be acceptable.  But what do
> you mean by "insertion only"?  Do you mean you''ll never
be reading from
> the table?  If so, why have it?
>
>
>
> > The association has the bag semantics.
>
> I''m not familiar with that term.  What do you mean?
>

It just means under a key there can be many items. That''s exactly what
I want, and it seems silly to have a primary key I don''t use. But
nevermind that, if rails insists, so be it.

>
>
> > If this doesn''t work, what''s "create_table :id
=> false"  ever used
> > for?
>
> For tables without AR models.  In a typical Rails app, that would only
> be habtm join tables.
>
> AR wants a primary key, and in any case, it''s poor practice not to
have
> one, even if it''s composite.
>
> Best,
> --
> Marnen Laibow-Koserhttp://www.marnen.org
> mar...-sbuyVjPbboAdnm+yROfE0A@public.gmane.org
>
> --
> Posted viahttp://www.ruby-forum.com/.