Subject: Re: pg_dump restore time and Foreign Keys
From: Simon Riggs <simon@2ndquadrant.com>
To: Heikki Linnakangas <heikki@enterprisedb.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
In-Reply-To: <48479381.6020006@enterprisedb.com>
References: <1212647003.19964.19.camel@ebony.site>
	<48479381.6020006@enterprisedb.com>
Content-Type: text/plain
Date: Thu, 05 Jun 2008 08:45:38 +0100
Message-Id: <1212651938.19964.34.camel@ebony.site>
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On Thu, 2008-06-05 at 10:19 +0300, Heikki Linnakangas wrote:
> Simon Riggs wrote:
> > I'm guessing that the WITHOUT CHECK option would not be acceptable as an
> > unprotected trap for our lazy and wicked users. :-)
> 
> Yes, that sounds scary.
> 
> Instead, I'd suggest finding ways to speed up the ALTER TABLE ADD 
> FOREIGN KEY. 

I managed a suggestion for improving it for integers only, but if
anybody has any other ideas, I'm all ears. 

> Or speeding up COPY into a table with foreign keys already 
> defined. For example, you might want to build an in-memory hash table of 
> the keys in the target table, instead of issuing a query on each INSERT, 
> if the target table isn't huge.

No, that's not the problem, but I agree that is a problem also.

> Nothing beats the speed of simply not checking the constraint, of 
> course, but I'd hate to lose the protection it gives.

Are you saying you don't like the rest of the proposal, or just don't
like the idea of having that added as an unprotected option, but find
the proposal acceptable? 

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Training, Services and Support