Re: SELECT Query taking 200 ms on PostgreSQL compared to 4 ms on Oracle after migration.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Justin/Bruce/Pavel,
Thanks for your inputs. After setting force_parallel_mode=off Execution time of same query was reduced to 1ms from 200 ms. Worked like a charm. We also increased work_mem to 80=MB. Thanks again.

Regards,
Aditya.

On Sat, Apr 3, 2021 at 9:14 PM aditya desai <admad123@xxxxxxxxx> wrote:
Thanks Justin. Will review all parameters and get back to you.

On Sat, Apr 3, 2021 at 9:11 PM Justin Pryzby <pryzby@xxxxxxxxxxxxx> wrote:
On Sat, Apr 03, 2021 at 11:39:19AM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@xxxxxxxxxx> writes:
> > On Sat, Apr  3, 2021 at 08:38:18PM +0530, aditya desai wrote:
> >> Yes, force_parallel_mode is on. Should we set it off?
>
> > Yes.  I bet someone set it without reading our docs:
>
> >     https://www.postgresql.org/docs/13/runtime-config-query.html#RUNTIME-CONFIG-QUERY-OTHER
>
> > --> Allows the use of parallel queries for testing purposes even in cases
> > --> where no performance benefit is expected.
>
> > We might need to clarify this sentence to be clearer it is _only_ for
> > testing.
>
> I wonder why it is listed under planner options at all, and not under
> developer options.

Because it's there to help DBAs catch errors in functions incorrectly marked as
parallel safe.

--
Justin

[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux