Subject: Re: ADD FOREIGN KEY (was Re: [GENERAL] 7.4Beta)
From: Hannu Krosing <hannu@tm.ee>
To: Andreas Pflug <pgadmin@pse-consulting.de>
Cc: Christopher Kings-Lynne <chriskl@familyhealth.com.au>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
In-Reply-To: <3F77F5A6.6070107@pse-consulting.de>
References: <200309281940.h8SJe3O01852@candle.pha.pa.us>
	<3F77ABA0.4070600@familyhealth.com.au>
	<3F77F5A6.6070107@pse-consulting.de>
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Date: Mon, 29 Sep 2003 12:57:13 +0300

Andreas Pflug kirjutas E, 29.09.2003 kell 12:04:
> Christopher Kings-Lynne wrote:
> 
> > You could just as easily argue that the lack of integrity testing at 
> > data load time was equally a bug.
> >
> > I think we need someway of telling postgres to suppress a foreign key 
> > check.
> >
> > The main problem is that the foreign key column is often not indexed. 
> 
> So a db designer made a bloody mistake.
> The problem is there's no easy way to find out what's missing.
> I'd really like EXPLAIN to display all subsequent triggered queries 
> also, to see the full scans caused by missing indexes.

It could probably be doable for EXPLAIN ANALYZE (by actually tracing
execution), but then you will see really _all_ queries, i.e. for a 1000
row update you would see 1 UPDATE query and 1000 fk checks ...

OTOH, you probably can get that already from logs with right logging
parameters.

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Hannu