Re: To estimate maximum active sessions on my oracle database is reasonable to the approach?
Date: Sat, 6 Nov 2021 09:48:05 +0000
Message-ID: <CAGtsp8=Ljdp-HamDQ4BM5XuGLZJgoZ24D1jSKKQk_QA3-7M6Hw_at_mail.gmail.com>
AAS can be as large as the sessions parameter (minus some value for the
background processes). Here's a query and result from an instance running
on a machine with 8 CPUs.
SQL> select sample_time, count(*) from V$active_session_history where
sample_time > sysdate - 10/(24*60*60) group by sample_time order by 1;
10 rows selected.
A session doesn't have to be "doing" anything to be active, it only has to
be in the middle of a database call. In this case all the sessions are
waiting on an attempt to "lock table X in exclusive mode" when the table is
already locked.
Regards
P.S. In case no-one answered: "IMHO" means "in my humble opinion".
On Mon, 1 Nov 2021 at 01:30, Quanwen Zhao <quanwenzhao_at_gmail.com> wrote:
> Concurrent is not matter ACTIVE?
SAMPLE_TIME COUNT(*)
-------------------------------- ----------
06-NOV-21 09.42.23.785 AM 11
06-NOV-21 09.42.24.809 AM 11
06-NOV-21 09.42.25.814 AM 11
06-NOV-21 09.42.26.817 AM 11
06-NOV-21 09.42.27.819 AM 11
06-NOV-21 09.42.28.827 AM 11
06-NOV-21 09.42.29.830 AM 11
06-NOV-21 09.42.30.847 AM 11
06-NOV-21 09.42.31.860 AM 11
06-NOV-21 09.42.32.869 AM 11
Jonathan Lewis.
>
> The logic cpus is 192 on my oracle database server, so AAS is allowed to
> increase to 192 because an AAS of 1 is equivalent to 100% of a CPU core.
> Since AAS has a maximum value I am also able to estimate the maximum
> concurrent connections using the current concurrent connections by the
> proportion with current AAS and logic cpus.
>
> By the way what's IMHO?
>
> Best Regards
> Quanwen Zhao
>
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Sat Nov 06 2021 - 10:48:05 CET