High Level Steps:
=================
Scenario 1: (When DB was up and running)
drop tablespace sysaux; ]]] Not possible
alter tablespace sysaux read only; ]]] Not possible
alter tablespace sysaux offline; ]]] Not possible

RMAN] alter database datafile 3 offline;
RMAN] restore datafile 3;
RMAN] recover datafile 3;
RMAN] alter database datafile 3 online;
SQL] alter database open;

Scenario 2: (When DB was down and No valid backup)
SQL] startup; ]]] Not possible
drop tablespace sysaux; ]]] Not possible
alter tablespace sysaux read only; ]]] Not possible
alter tablespace sysaux offline; ]]] Not possible

RMAN] alter database datafile 3 offline;
RMAN] restore datafile 3; ]]] which will fail since we don’t have valid backup
RMAN] recover datafile 3; ]]] which will fail since we don’t have valid backup
RMAN] alter database datafile 3 online; ]]] Fails with unable to find a file
alter database open;
select name, open_mode from v$database; ]]] Able to open the DB

Please refer the below blog for more details:
https://mallik034.blogspot.com/2022/02/man-recovery-scenario-sysaux-datafile.html

#Corruption #RMAN #sysaux #Recovery #DatafileCorruption #Restore #Recovery #ASM #Oracle #RAC #Database #Exadata #ASM

Regards,
Mallikarjun Ramadurg
Mobile: +91 9880616848
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