Reduce downtime required for support patch application

Question

Dear Experts,
I would like to know if there are any tips / notes we need to follow during application of
support patches to reduce the downtime window ( as during patch application , system is not
usable for normal users ) , any temparary parameter changes to Oracle RDBMS which we can
activate before appication of support patch and then revert the same once Patches are loaded
for normal Day operations.
Is there any note which talks specific settings which could enhance the performance
of support patch application process on Oracle RDBMS.
Regards,
RR

Answer 1

To my understanding if i select Downtime minimized some phases of Patch application could
be carried out when users are online and for others would get notified in SPAM for downtime
, so we just need to lock users and perform start for those rest of Import phases.
Yes this is correct, theoretically you can apply single patches with downtime minimized one after another. But this does not make a lot of sense obviously, because you will have several distinct downtimes then. So to apply one queue containing all packages is the way to go.
Regarding your questions on the benefits, i am afraid the answer here is: it depends, as for most performance tuning options you will have to test carefully if the are working.
For the db_cache_size consider:
- is my db_cache_size smaller than 1000M?
- do i have enough free memory on my server?
- am i seeing low buffer hit ratio while applying support packages?
If all questions are a yes, then i recommend you increase it to 2000M, it is easy to do. But if you don't have free memory on the server, then you will severly hurt performance by causing paging. If you don't have low buffer hit ratio (or you have lightspeed disks , then the tuning will not speed up anything.
As you see, you have options, but there isn't a single speed button that solves your problem.
Regards, Michael