Thread: Re: RFC: Allow EXPLAIN to Output Page Fault Information

Re: RFC: Allow EXPLAIN to Output Page Fault Information

From
Tom Lane
Date:
torikoshia <torikoshia@oss.nttdata.com> writes:
> I have attached a PoC patch that modifies EXPLAIN to include page fault 
> information during both the planning and execution phases of a query. 

Surely these numbers would be too unstable to be worth anything.

            regards, tom lane



Re: RFC: Allow EXPLAIN to Output Page Fault Information

From
torikoshia
Date:
On 2024-12-25 00:52, Tom Lane wrote:
> torikoshia <torikoshia@oss.nttdata.com> writes:
>> I have attached a PoC patch that modifies EXPLAIN to include page 
>> fault
>> information during both the planning and execution phases of a query.
> 
> Surely these numbers would be too unstable to be worth anything.

Thanks for your comment!

Hmm, I didn't know these are unstable. If there are any reasons, I'd 
like to know about them.

I would like to explore alternative methods for measuring resource 
usage, but
I am not aware of other approaches.
(IIUC pg_stat_kcache[1], which is said to provide information about 
filesystem layer I/O usage also gets metrics from getrusage(2))


[1] https://github.com/powa-team/pg_stat_kcache

-- 
Regards,

--
Atsushi Torikoshi
Seconded from NTT DATA GROUP CORPORATION to SRA OSS K.K.