Re: pg_dump: Sorted output, referential integrity
Stephan Szabo <sszabo@megazone23.bigpanda.com>
From: Stephan Szabo <sszabo@megazone23.bigpanda.com>
To: Jan Wieck <janwieck@yahoo.com>
Cc: Philip Warner <pjw@rhyme.com.au>, Christof Petig <christof@petig-baender.de>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2001-12-11T18:30:38Z
Lists: pgsql-hackers
On Tue, 11 Dec 2001, Jan Wieck wrote: > Stephan Szabo wrote: > > > > On Tue, 11 Dec 2001, Philip Warner wrote: > > > > > At 13:34 7/12/01 -0800, Stephan Szabo wrote: > > > > > > > >Well, the biggest thing I see on using alter table add constraint for > > > >foreign keys is the expense involved if you do it after the tables are > > > >populated. > > > > > > Is it really worse than loading the tables with the constraint in place? > > > > I'd say its better than while loading, but currently the check isn't > > performed at all I think, because the create constraint trigger > > statements are after data load and they don't check the data at all. > > At least that's how I remember it, I could be wrong. > > You're not. This discussion came up a couple of times, and > the answer is allways the same. > > We don't want to define the constraints with ALTER TABLE > because this means checking data on restore that doesn't need > to be checked at all (in theory). If he has a crash of a > critical system and restores from a dump, I bet the farm that > he wants it FAST. I'd say as an optional parameter to dump, it's definately not a bad idea (like the idea of a --sql or whatever) since the user has to explicitly ask for it. I think for the rest of the cases it comes down to what people want it to do.