You can benchmark your scenario with and without constraint using a tool like nancy:
it lets you A/B test different configurations with your own scenarios or using pgbench synthetic workloads.
-Michel
On Wed, Jul 22, 2020 at 9:27 AM Samuel Nelson <valczir.darkvein@xxxxxxxxx> wrote:
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.-Samhttps://github.com/nelsam
"As an adolescent I aspired to lasting fame, I craved factual certainty, and
I thirsted for a meaningful vision of human life -- so I became a scientist.
This is like becoming an archbishop so you can meet girls."
-- Matt CartmillOn Wed, Jul 22, 2020 at 10:31 AM David G. Johnston <david.g.johnston@xxxxxxxxx> wrote:On Wed, Jul 22, 2020 at 8:24 AM Samuel Nelson <valczir.darkvein@xxxxxxxxx> 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.David J.
