Re: Why is DEFAULT_FDW_TUPLE_COST so insanely low? - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Why is DEFAULT_FDW_TUPLE_COST so insanely low?
Date
Msg-id ZT-3KgndQLQ_bnFy@momjian.us
Whole thread Raw
In response to Re: Why is DEFAULT_FDW_TUPLE_COST so insanely low?  (David Rowley <dgrowleyml@gmail.com>)
Responses Re: Why is DEFAULT_FDW_TUPLE_COST so insanely low?
List pgsql-hackers
On Mon, Oct 30, 2023 at 02:22:08PM +1300, David Rowley wrote:
> If I change STD_FUZZ_FACTOR to something like 1.0000001 then the plans
> no longer change when I do:
> 
> alter server loopback options (add fdw_tuple_cost '0.01');
> <run the query>
> alter server loopback options (drop fdw_tuple_cost);
> <run the query>
> 
> Ordinarily, I'd not care too much about that, but I did test the
> performance of one of the plans and the new plan came out slower than
> the old one.
> 
> I'm not exactly sure how best to proceed on this in the absence of any feedback.

I think you just go and change it.  Your number is better than what we
have, and if someone wants to suggest a better number, we can change it
later.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EDB                                      https://enterprisedb.com

  Only you can decide what is important to you.



pgsql-hackers by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: COPY TO (FREEZE)?
Next
From: Alexander Korotkov
Date:
Subject: Re: POC, WIP: OR-clause support for indexes