[QUOTE][i]Originally posted by mary [/i]
[B]1)since there is an alert log for each instance in your example oracle sid is the name of the instance. Is it correct? [/B][/QUOTE]
Yes
[QUOTE][B]
2)Is it being assigned by default and dba should not ever rename it? When is that name being created/assigned?
Thank you. [/B][/QUOTE]
No, you should never rename it. It is maintained by Oracle and is created when the database is created.