Re: On disable_cost

On 8/23/24 2:29 PM, Robert Haas wrote:
> On Fri, Aug 23, 2024 at 2:20 PM Jonathan S. Katz <jkatz(at)postgresql(dot)org> wrote:
>> I don't think extension maintainers necessarily have the same level of
>> PostgreSQL internals as you or many of the other people who frequent
>> -hackers, so I think it's fair for them to ask questions or raise issues
>> with patches they don't understand. I was able to glean from the commit
>> message that this was the commit that likely changed the behavior in
>> pgvector, but I can't immediately glean looking through the code as to
>> why. (And using your logic, should an extension maintainer understand
>> the optimizer code when PostgreSQL is providing an interface to the
>> extension maintainer to encapsulate its interactions)?
>>
>> You can always push back and say "Well, maybe try this, or try that" -
>> which would be a mentoring approach that could push it back on the
>> extension maintainer, which is valid, but I don't see why an extension
>> maintainer can't raise an issue or ask a question here.
>
> I'm certainly not saying that extension maintainers can't raise issues
> or ask questions here. I just feel that the problem could have been
> analyzed a bit more before posting.

This assumes that the person posting the problem has the requisite
expertise to determine what the issue is. Frankly, I was happy I was
able to at least trace the issue down to the particular commit and
brought what appeared to be a reliable reproducer, in absence of knowing
if 1/ this was actually an issue with PG or pgvector, 2/ does it
actually require a fix, or 3/ what the problem could actually be, given
a lack of understanding of the full inner working of the optimizer.

Based on the above, I'm not sure what bar this needed to clear to begin
a discussion on the mailing list (which further downthread, seems to be
raising some interesting points).

Jonathan