Re: Foreign key slows down copy/insert

From: Richard van den Berg <richard(dot)vandenberg(at)trust-factory(dot)com>
To: Christopher Kings-Lynne <chriskl(at)familyhealth(dot)com(dot)au>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Foreign key slows down copy/insert
Date: 2005-04-14 14:26:30
Message-ID: 425E7D96.6020201@trust-factory.com
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Hello Chris,

Thanks for your answers.

Christopher Kings-Lynne wrote:
> Deferring makes no difference to FK checking speed...

But why then is the speed acceptable if I copy and then manually add the
FK? Is the check done by the FK so much different from when it is done
automatically using an active deffered FK?

> Well, that's what people do - even pg_dump will restore data and add the
> foreign key afterward...

If I have to go this route, is there a way of automatically dropping and
re-adding FKs? I can probably query pg_constraints and drop the
appropriate ones, but how do I re-add them after the copy/insert?

Sincerely,

--
Richard van den Berg, CISSP
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