>
> Hmm. The planner should avoid using a merge join if it knows that
> to be true. Maybe analyze'ing that table would prompt it to use
> some other join method?
The planner has updated stats on the table and wants to use a nested loop:
https://explain.dalibo.com/plan/3814d5356cc82528
But t
Dane Foster writes:
>> If the sort is the inner input to a merge join, this could reflect
>> mark-and-restore rescanning of the sort's output. Are there a
>> whole lot of duplicate keys on the merge's other side?
> Yes. The course_id column's values repeat a LOT on the merge side.
Hmm. The pla
> If the sort is the inner input to a merge join, this could reflect
> mark-and-restore rescanning of the sort's output. Are there a
> whole lot of duplicate keys on the merge's other side?
Yes. The course_id column's values repeat a LOT on the merge side.
Dane
On Fri, Aug 4, 2023 at 11:10 AM
Dane Foster writes:
> I'm trying to understand a bit of weirdness in a plan output. There is a
> sort node above a sequential scan node where the scan node produces 26,026
> rows yet the sort node above it produces 42,995,408. How is it possible to
> sort more data than you received?
If the sort
Thanks for the explanation.
Dane
On Fri, Aug 4, 2023 at 11:07 AM Jeff Janes wrote:
> On Fri, Aug 4, 2023 at 11:00 AM Dane Foster wrote:
>
>> Hello,
>>
>> I'm trying to understand a bit of weirdness in a plan output. There is a
>> sort node above a sequential scan node where the scan node pro
On Fri, Aug 4, 2023 at 11:00 AM Dane Foster wrote:
> Hello,
>
> I'm trying to understand a bit of weirdness in a plan output. There is a
> sort node above a sequential scan node where the scan node produces 26,026
> rows yet the sort node above it produces 42,995,408. How is it possible
> to sort
Hello,
I'm trying to understand a bit of weirdness in a plan output. There is a
sort node above a sequential scan node where the scan node produces 26,026
rows yet the sort node above it produces 42,995,408. How is it possible to
sort more data than you received?
https://explain.dalibo.com/plan/1
