Re: Memory needed for upgrade to 18c

Hello Thanh,

to point 1) Even if you have not changed any parameter you might have an increase in PGA usage as PGA_AGGREGATE_TARGET is just a soft-limit and you get different execution plans with more PGA usage, etc.

to point 2) The idea is already simple as you don't need to check all processes. Just grep one from a 12.1.0.2 instance and grep the same process (e.g. a plain connected process/session without any workload) from a 18c instance and compare with svmon. That's it.

Best Regards
Stefan Koehler

Independent Oracle performance consultant and researcher Website: http://www.soocs.de
Twitter: _at_OracleSK

> Thanh NGUYEN <ttrnguyen_at_gmail.com> hat am 18. Mai 2019 um 09:17 geschrieben:
>
> Hello Stefan,
> Thank you very much for your answer.
>
> 1) We did not change any parameter related to memory. Furthermore, we got the same issue (memory usage increased), 2 years ago, when we upgraded from 11.2.0.4 to 12.1.0.2.
>
> 2) We have 22 single instances at that server. It will take time if we determine the the consumption of each process.
>
> Do you have any simpler idea?
>
> Best regards,
>
> Thanh NGUYEN
>
> ------------------------
>
> $ ps -ef|wc
>     3423   30419  238850
> 8:58:13 z004969:/users/ucib/z004969
> $ ps -ef|grep smon|grep -v grep|wc
>       22     198    1498

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