Re: CASCADE/fkey order

I checked, and changing the `bazinga_foo_bar` constraint to:

alter table bazinga add constraint bazinga_foo_bar foreign key (foo_id, bar_id) references foo_bar (foo_id, bar_id) deferrable initially deferred;

seems to fix it to work as we were expecting.  Is that particularly costly?  Should I only set the constraint to be deferred when we really need it?  Would it be more efficient to perform the deletes explicitly within a transaction rather than relying on the cascades and deferring that one constraint?

Our resident ex-Oracle DBA said that deferred constraints used to be heavily recommended against, but he also admitted that he hasn't kept up with that in the past 10 years.

-Sam

https://github.com/nelsam

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On Wed, Jul 22, 2020 at 10:31 AM David G. Johnston <david.g.johnston@gmail.com> wrote:

On Wed, Jul 22, 2020 at 8:24 AM Samuel Nelson <valczir.darkvein@gmail.com> wrote:

Is there a way to force the delete to cascade to tables in a specific order?

No really, but you can defer constraint checking.

https://www.postgresql.org/docs/12/sql-set-constraints.html 

David J.