Thank You Mark. Actually I had attached the sql monitors for three queries
and I am not seeing major deviation in resource consumption of index access
in those paths. But I did pick up a few indexes in the database and tried
to see the clustering factor and leaf block count history from
WRI$_optstat_ind_history , to see if post TSE there is a major increase in
those but didn't find any such difference. And in these sql monitors it's
the last execution path which shows an increase in read bytes in the line
where it's doing "table access storage full first rows' '. But again i was
trying to see if the number of blocks has been increased from
WRI$_optstat_tab_history post TSE , but unfortunately it seems we don't
gather stats frequently in this table , so not getting entry in this awr
view for this table.
Regards
Lok
On Mon, Jun 28, 2021 at 9:03 AM Mark W. Farnham <mwf@xxxxxxxx> wrote:
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
