Re: pg_dumpall and check constraints

Philip Warner wrote:

> At 09:59 30/06/00 +0200, Guillaume Perréal wrote:
> >>>>
>
> And the question is: Is there a better way to do what I want (checking field values from different tables against data in one table) that allow pg_dumpall to works ?
>
> <<<<
>
> I'm not sure what to suggest, but a FOREIGN KEY constraint might help. You would need to do one of two things:
>
> 1. add fieldname to the definition of station, then use
> FOREIGN KEY ("fieldname", "type") references "information" (fieldName, code),

Well, I don't think adding the same value to each row of "station" is the better solution. But it's a solution.

>
> OR
>
> 2. create a view:
> create view "station_fields" as select * from information where fieldname = 'station.type';
>
> then use:
>
> FOREIGN KEY ( "type") references "station_fields" ( code),

I tried : it doesn't work. It seems that view rows don't have OID, which are used in foreign key. (I deduce that from the error messages I've got when I tried).

>
>
> You'd need to assess the permance issues associated with each choice - some DB systems don't do views very well, and I have absolutely no experience with big views under PG.

"information" won't be a big view : less than one hundred tuples.

>
>
> FWIW, I have just finished writing a modified pg_dump which restores things in a variety of possibl orders, and works with the example you quoted.
>
> I'm just waiting on volunteers to test it...

Why not? But I can't promise you to do full testing as I've got a lot of work these days.

Thanks.

--
Guillaume Perréal - Stagiaire MIAG
Cemagref (URH), Lyon, France
Tél: (+33) 4.72.20.87.64