Alexey Bashtanov <> writes:
> Is there a reason that join cardinality estimates are not limited by the 
> product of the joined parts cardinalities like in the 
> join-card-est.patch attached?

Because that would be giving an unfair advantage to some paths over
others based on nothing except estimation errors.  I do not think we'd
get a net benefit in plan quality.

If we could do this earlier and adjust the join relation's overall
cardinality estimate, it might be something to consider.

                        regards, tom lane

Sent via pgsql-hackers mailing list (
To make changes to your subscription:

Reply via email to