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Back up the control file

posted Jul 12, 2011, 1:44 PM by Sachchida Ojha

When you issue the command

alter database backup control file to trace;

the script that is generated does not include the information in the control file that identifies your backups. Without these backup records, you cannot access the backups when they are needed for recovery. All RMAN information is lost, and you cannot get it back. The only RMAN information that gets rebuilt when you rebuild the control file is any permanent configuration parameters you have set with RMAN. In Oracle 1 0g and higher, a new mechanism generates limited backup metadata within a control file, but you are still building in a lot of manual work that never used to exist. Therefore, we encourage you to avoid a control file rebuild at all costs.

If you back up the control file to a binary file, instead of to trace, then all backup information is preserved. This command looks like the following:

alter database backup controlfile to ' /u01/backup/bkup_cfile. ctl' ;