Originally posted by jigarpota
Hi,

Probably you need to reinstall the database.

But before that please checkout the process with pis=4220 is running or not if it is running kill that process and try again.

Hope this helps

Regards,
It clearly indicates that the process 4220 was of PMON which killed the instance. And when the instance went down PMON will go down by itself.

As to handle the main question. Better log a priority 1 iTAR. If possible try recovering the database using archived log files if in archived mode, if not then only way to recover would be to restore the cold backup.