Noted thanks!!
On Sun, Apr 4, 2021 at 4:19 PM Pavel Stehule
wrote:
>
>
> ne 4. 4. 2021 v 12:39 odesílatel aditya desai napsal:
>
>> Hi Pavel,
>> Notes thanks. We have 64 core cpu and 320 GB RAM.
>>
>
> ok - this is probably good for max thousand connections, maybe less (about
> 6 hundred). Postgres doesn't perform well, when there are too many active
> queries. Other databases have limits for active queries, and then use an
> internal queue. But Postgres has nothing similar.
>
>
>
>
>
>
>
>> Regards,
>> Aditya.
>>
>> On Sat, Apr 3, 2021 at 11:21 PM Pavel Stehule
>> wrote:
>>
>>>
>>>
>>> so 3. 4. 2021 v 19:45 odesílatel aditya desai
>>> napsal:
>>>
Yes. I have made suggestions on connection pooling as well. Currently
it is being done from Application side.
>>>
>>> It is usual - but the application side pooling doesn't solve well
>>> overloading. The behaviour of the database is not linear. Usually opened
>>> connections are not active. But any non active connection can be changed to
>>> an active connection (there is not any limit for active connections), and
>>> then the performance can be very very slow. Good pooling and good setting
>>> of max_connections is protection against overloading. max_connection should
>>> be 10-20 x CPU cores (for OLTP)
>>>
>>> Regards
>>>
>>> Pavel
>>>
>>>
>>>
>>>
On Sat, Apr 3, 2021 at 11:12 PM Pavel Stehule
wrote:
>
>
> so 3. 4. 2021 v 19:37 odesílatel aditya desai
> napsal:
>
>> 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
>>
>
> super.
>
> The too big max_connection can cause a lot of problems. You should
> install and use pgbouncer or pgpool II.
>
>
> https://scalegrid.io/blog/postgresql-connection-pooling-part-4-pgbouncer-vs-pgpool/
>
> Regards
>
> Pavel
>
>
>
>
>> again.
>>
>> Regards,
>> Aditya.
>>
>> On Sat, Apr 3, 2021 at 9:14 PM aditya desai
>> wrote:
>>
>>> Thanks Justin. Will review all parameters and get back to you.
>>>
>>> On Sat, Apr 3, 2021 at 9:11 PM Justin Pryzby
>>> wrote:
>>>
On Sat, Apr 03, 2021 at 11:39:19AM -0400, Tom Lane wrote:
> Bruce Momjian 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
>>>
