SQL> show parameter background_dump_dest;
what ever location is showing check in that location. In this location you might find the old alerts also, make sure you are checking the latest right file. and you for testing once switch the logfile. SQL> alter system switch logflie. then check the alert log.
refer: Who writes alert log file?
I would begin with a simple test of whether you can, on demand, write to the alert log and to a trace file:
alter system set diagnostic_dest='c:\tmp'; --use any directory you want, that exists and on which Oracle has write permission
exec dbms_system.ksdwt(3,'my message')
the argument 3 means append the message to the alert log and also write it out to a trace file. That will create directories beneath the diagnostic_dest with a new alert log and a trace file. If this works, then I think you have a problem your existing diagnostic_dest value.
Can someone please help me how to resolve this...
You posted this follow-up a mere 28 minutes after your previous post.
This forum is not a chat line, and it is not paid support.
Everyone here has a job for which they are paid, and this forum is not it.
No one is responsible for monitoring it and giving a quick response.
Furthermore, it is a global forum. The person with the information you seek may very well live 20 time zones away from you and was going to bed just as you posted. He will not even see your post for several more hours.
Your original post went up in the middle of the night for half the world -- on a weekend ....
No one with the information you seek is deliberately withholding it until you sound sufficiently desperate.
Sorry everyone for my late update.I was away from my work this week and could not update this post.
It was my mistake in looking at the alert log location.I added the db_unique_name parameter in my pfile and the alert log file location was changed because of this parameter and I was looking at the old alert log.
after sometime,I identified this error.Thank you everyone for your time.
My sincere apologies.