Preventing data loss due to block corruption (Best Practices)
There are some important aspects that should be verified up front in order to have a clean up Oracle database and consequently prevent data loss due to corruptions, consider following recommendation.
- Run a FULL database consistency check during a backup cycle (once at least);
- Always ensure to have a valid backup in place, by performing a consistency check of the database backups. This is VERY IMPORTANT and will for sure avoid unusable backups;
- You should schedule ‘Validate Structure’ and ‘Verify database’ via DB13 to perform such checks;
- Using RMAN is also a possible way to easily check the database backups and perform the consistency check, you can use brbackup option ‘-w only_rmw’;
- The usage of BR*tools (brbackup, brconnect) is recommended for such checks, do not perform manual checks if possible;
- It is also very important to perform regular OS/Hardware checks as corruptions are mostly related to such areas.
All detailed information concerning consistency checks is described on SAP Note 23345.
Concerning cases that corruption is found, SAP recommendation is to read carefully SAP Note 365481 and proceed exactly as per solution provided.
There are some cases that unnecessary restore/recovery actions are taken and lead to big problems and data loss, so unless you are sure about the steps you are about to take otherwise contact SAP support.