Thank you. Got it.
So is it correct to say that the cache warmup we are talking about here is
mainly DB buffer cache. And yes, we can ignore the first 30 minutes of
workload replay. Btw I have heard the storage cell flash cache needs many
hours to be populated with the required blocks , storage indexes etc during
the initial point. So my question was, if it's going to wipe out the flash
cache also in case of DB flashback ? Or as Pap mentioned these are
persistent storage so they won't get wiped off like DB buffer cache in case
of DB flashback to past point in time?
On Mon, Nov 1, 2021 at 3:28 AM Ls Cheng <exriscer_at_gmail.com> wrote:
> Hi
>
> I think you should capture RAT for at least 3, 4 hours of workload. In the
> old days when load tests were using tools such as Mercury Loadrunner there
> was a stage in the beginning which we called ramp-up which is the warming
> up stage you are describing to bring in live-like conditions. During
> ramp-up response times are higher and are taken into account when analyzing
> the data.
>
> So to simplify things, run AWR every 30 minutes and consider the first 30
> minutes as your ramp-up stage.
>
> Thanks
>
>
> On Sun, Oct 24, 2021 at 12:32 PM Lok P <loknath.73_at_gmail.com> wrote:
>
>> Hi, We are planning to use the real application testing feature of Oracle
>> for capturing and replaying production workloads to see the actual impact
>> of one of our coming versions and hardware upgrades. We have one question-
>> As before each workload replay the RAT database has to be flashed back to
>> the point in time where we have captured the workload from. So will that
>> flashback, remove everything from the RAT DB buffer cache and also
>> everything will be wiped out from the storage server flash cache? And in
>> that case the replay may not mimic the exact impact as the cache warmup
>> will be adding additional overhead to the resource and time and thus it may
>> not be a good comparison of before and after upgrade behaviour of RAT
>> database. Can you please confirm if this is the correct understanding and
>> how we should replay then to avoid this cache warmup thing? And if any
>> other RAT system related resources can also deviate the figures?
>>
>> Regards
>> Lok
>>
>
