Question: After creating a controlfile manually without any backup how the database goes to a consistent state? Because the newly created controlfile does not have the scn details as well as checkpoint information that the deleted controlfile had.
Also after restoring the controlfile is it needed to open the database in resetlogs mode? If not why?
Good question
I too was very focusing on this one when I restore controlfile and open the database with resetlogs and I try to open with noresetlogs but no luck.
With this point I clear my doubt and according to my understanding if you recreated controlfile or restore from autobackup the scn and ckpt information is different.
Anyway a control file restored from a backup has an SCN taken at that "remote" time, different compared with those currently available in the datafiles and redo logs and so they have to be resynchronized.
To resynchornized controlfile with redologs and datafiles we need to do resetlogs and you know resetlogs: "RESETLOGS will initialize the logs, reset your log sequence number, and start a new "incarnation" of the database."
Also after restoring the controlfile is it needed to open the database in resetlogs mode? If not why?
Good question
I too was very focusing on this one when I restore controlfile and open the database with resetlogs and I try to open with noresetlogs but no luck.
With this point I clear my doubt and according to my understanding if you recreated controlfile or restore from autobackup the scn and ckpt information is different.
Anyway a control file restored from a backup has an SCN taken at that "remote" time, different compared with those currently available in the datafiles and redo logs and so they have to be resynchronized.
To resynchornized controlfile with redologs and datafiles we need to do resetlogs and you know resetlogs: "RESETLOGS will initialize the logs, reset your log sequence number, and start a new "incarnation" of the database."
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