Tomas Vondra <tv@fuzzy.cz> writes:
> On 25.12.2014 20:36, Tom Lane wrote:
>> BTW, I notice that in the current state of pgstat.c, all the logic
>> for keeping track of request arrival times is dead code, because
>> nothing is actually looking at DBWriteRequest.request_time.
> Really? Which part of the code is dead? I see pgstat_recv_inquiry() is
> updating the request_time after receiving the inquiry, and
> pgstat_db_requested() is looking at it when writing the files.
Where is pgstat_db_requested() looking at request_time?
> If we can simplify the code by keeping just OIDs, let's do that. I think
> the main reason why we haven't done that in 187492b6 was to keep as much
> of the existing logic (and maybe change it in a separate patch).
The real point here is that I think that commit *already* changed the
existing logic, because the time-of-receipt used to matter. In
particular, there used to be a throttle on how often the stats file
could get written, which seems to have vanished. I seriously doubt
that that was a good change, especially on write-bandwidth-challenged
platforms.
regards, tom lane
