Re: Same query with different response time

There are four points to investigate in your Monitor repors:

1. Why are your "TABLE ACCESS STORAGE FULL"s qualified by "FIRST ROWS" -- this feature may have some bearing on the preformance.
2. Why are your tablescans (before tse) doing an average of about 128KB per read request while the index fast full scan is going for 1MB ? Is this related to FIRST ROWS
3. One (and only one) of your tablescans (after tse) using 1MB read requests - what's different about that one?
4. The buffer gets value is consistent with the "read bytes" in all cases, which suggests you're not getting any benefit from the storage cells (cell offload/storage indexes).

> 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
>

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