----- On 10 Apr, 2019, at 10:23 AM, Andres Freund andres@anarazel.de wrote:
> On 2019-04-09 17:12:27 -0500, Justin Pryzby wrote:
>> You could test that's the issue by comparing with fsync=off (please read what
>> that means and don't run your production cluster like that).
>> https://www.postgresql.org/docs/current/runtime-config-wal.html#GUC-FSYNC
>
> I suggest testing it with synchronous_commit=off instead. That's about
> as fast for this type of workload, doesn't have cluster corruption
> issues, the window of a transaction not persisting in case of a crash is
> very small, and it can just set by any user in individual sessions.
Bingo! Adding 'SET LOCAL synchronous_commit TO OFF;' to my 'BEGIN; UPDATE ....; COMMIT;' block has given me sub-1ms
timings!Thanks Andres.
I'll probably leave the setting as that on my local machine. The option appears to be relatively safe, but my machine
isjust a dev test machine anyway.
Regards,
Duncan Kinnear