Hello,

We are facing performance issues on our database.

Our application is designed in such a way that it is rigorously used only for 5-days in a month and while it is used there are around 300 sessions running in parallel at any point of time.
Usually application performance is as expected but at some times we were able to sense performance lag during which multiple sessions could be seen having queries under LongOps tab in session browser (in Toad).

while the performance issue is happening we found RMAN job session(s) active hence we are of opinion that the performance lag is due to RMAN job running. I am not an expert on Oracle DBA concepts, below is some information about RMAN job in our environment

1. The RMAN job runs once a day and usually takes around 20mins to complete.
2. But on occasions it get initiated automatically when Archive Log (300GB) is full [archive log is full on any of 5-days when application is used].
3. Now, the RMAN jobs takes around 2hours to complete.
4. During this time we see sharp increase in I/O events.

Hence while RMAN job is running it effects the performance of other active session.

We were wondering if it is possible to disable RMAN for those 5-days, if yes then how?

Please suggest if possible other reason/solution.

--Imran.