Are any indexes used in your plans and if so, did the cluster factors change?
IF you have block visits minimized via an index prior to TSE but after TSE it
has to skip around a lot more, that *could* explain changes in CPU and IO with
no change in plan.
Just a thing to check, probably not it but worth a glance.
mwf
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Lok P
Sent: Sunday, June 27, 2021 10:19 PM
To: Pap
Cc: Oracle L
Subject: Re: Same query with different response time
No other change happened. It was only tablespace encryption which has been done
on top of existing data.
I am also struggling to understand why the increase in IO is noted in SQL
monitor.
Regards
Lok
On Sun, 27 Jun 2021, 8:22 am Pap, <oracle.developer35@xxxxxxxxx> wrote:
I would expect a little more CPU requirement for any encryption/decryption
activity. But in your SQL monitor it's also showing difference in IO. Not sure
if it can only attributed to tablespace encryption. Any other change happened?
On Sat, 26 Jun 2021, 7:49 pm Lok P, <loknath.73@xxxxxxxxx> wrote:
Hello Listers, We have seen TSE (tablespace encryption) implementation in the
past in multiple databases but have not verified any performance aspect of this
and we have also not got any complaint and now this has been mandated by the
security team to do it for all the databases. However, we recently migrated one
of the database to TSE i.e. tablespace encryption(Not column level TDE) and
it's the lower environment/dev database, and dev team sent us few sql monitors
noting performance degradation post TSE (some were ~100% slower which we were
not expecting).
Attached are a few of the sql monitors which we got , stating the execution
plan is same and volume is same , yet there is significant increase in response
time. So I am not sure if we can validate from the sql monitor report, if the
increase in execution time is only because of tablespace encryption or anything
else. So can you please guide me here, how i can validate from this attached
sql monitor if the degraded response time is because of TSE/tablespace
encryption or anything else and how we can fix this issue?
It's version 19.9.0.0.0 of Oracle.
Regards
Lok
