We are running Oracle EBS 12.1.1 with database release 220.127.116.11 on Solaris Sparc 10 OS. I have noticed that every day at 8:00am application gets literally very slow even the login page itself takes around 15 minutes to login into the application. I have noticed the following parameter in my database alert log file.
Wed Jun 27 08:00:00 2012 Setting Resource Manager plan SCHEDULER[0x56D90]:DEFAULT_MAINTENANCE_PLAN via scheduler window Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter Wed Jun 27 08:00:04 2012 Begin automatic SQL Tuning Advisor run for special tuning task "SYS_AUTO_SQL_TUNING_TASK" Wed Jun 27 08:18:21 2012
I have also noticed that the above task starts every day at the same time in the alert log file.
Please help me to understand the reason of the above scheduler. Is this effecting the performance of application? if yes then how to change its timings or is it necessary? What is going to happen if i disable the resource manager?
I would also like to add that the performance issue remains almost for an hour and then application works fine without any issue.