Or is it suggested to use variable IORM objectives throughout the day, say
setting objective "LOW LATENCY" during OLTP load and "HiGH THROUGHPUT"
during batch load. So is this possible and advisable to set/change the IORM
in such a way through some automated process multiple times in a day?
On Fri, Nov 20, 2020 at 1:28 AM Lok P <loknath.73@xxxxxxxxx> wrote:
It looks to me as if DB resource managers are purely made for CPU
management, and with that respect , I doubt it will be effective in
managing the storage cell I/O, and that is why IORM(IO resource manager)
has come into picture. But sadly it's not documented properly. And in most
of the cases it says it manages inter database workload only. But we are
facing issues with intra database workload management. I got below blog
stating how AUTO objectives for IORM fixed the issue of IO management. So
has anybody used AUTO objective for managing INTRA databases workload?
https://weidongzhou.wordpress.com/2013/08/23/awr-is-not-enough-to-track-down-io-problem-on-exadata/
On Thu, Nov 19, 2020 at 2:29 AM Lok P <loknath.73@xxxxxxxxx> wrote:
We have one database with version 11.2.0.4 Exadata-X5 machine. We have
IORM objective kept as BASIC(which is default) and it's only one database
in that half RACK(~7 cell server) exadata cluster. We encountered
performance issue twice , where a ETL query doing FULL table/partition scan
repetitively for longer duration, causing the flash cache to be flooded
with large reads and the other low latency work load or small reads/index
reads getting suffered because of that, and so we had to kill the ETL query
to let the low latency workload perform in its normal speed.
I saw in a few blogs stating the IORM should be kept as AUTO and is
recommended. Wanted to understand from experts, if AUTO IORM setup is going
to help in such a situation, where we have only one database residing in
the exadata machine having multiple types of workloads(both OLTP and BATCH
types at same time) running in the same database? I am not seeing a clear
difference , how different is IORM objective AUTO from the BASIC incase of
single database IORM management?
