Re: Foreign Keys Constraints, perforamance analysis - Mailing list pgsql-general

From Daniel Åkerud
Subject Re: Foreign Keys Constraints, perforamance analysis
Date
Msg-id 012001c0fd95$107c9b50$c901a8c0@automatic100
Whole thread Raw
In response to Re: Foreign Keys Constraints, perforamance analysis  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
List pgsql-general
> > OK, I've been discussing this with a collegue of mine... and I'm
starting to
> > see the light here...
> >
> > I will, first of all, make a new, simpler, 1<->1 realtionship to test FK
> > constraints... no 2<->1<->2 relasionship here...
> >
> > Person -> Item/item_fkc
> >
> > And I will do no bulk-delete. Instead these tests:
> >
> > Fill person. no time measuring.
> > Fill item, no foreign keys constraints, time measuring.
> > Fill item, foreign keys constraints
> > Compare last to measurments. How much do you loose in performance having
the
> > Foreign Key check?
> > For all persons {
> >   if (fkc)
> >     delete from person where id = $id
> >   else
> >      delete from person where id = $id; delete from item where
personid=$id
> > }
> > Compare measurements. How much do you loose having the foreign keys
> > constraints delete the item?
> >
> > This, I think, this is a more fair comparison.
> >
> > Can you call the FK itself a foreign key constraint, as it actually is
> > constraining something?
>
> Yeah, that's a more even test.  Since it sounds like you're writing
> something on foreign key constraints (presumably about postgres), you
> might want to mention the differences with table clearing deletes
> but point out the foreign key constraints aren't generally used in
> schemas where you're doing that :)
>
> As for naming, I'd think so.  It is a constraint, just that
> "foreign key constraint" is much longer to type than FK :)
>

Thanks :)

Daniel Åkerud



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