ORA-01578 after rman recovery

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Oracle - 11.2

This is a brief list pointing out some factors on nologging operations which results unrecoverability in database. Once a db backup with unrecoverable operations fully recovered, accessing affected objects will still return ORA--1578.

1. Detecting unrecoverable operations.

Rman "report unrecoverable" will provide list of datafiles which are in unrecoverable state.

Also unrecoverable_time column of v$datafile can be queried to see the last unrecoverable action performed on particular datafile, but this column will not be updated after a backup is made from rman.

2. There want be any errors during the restore/recovery operations in rman  logs.

Even during a nologging operation small amount of redo is generated. These logs simply says that affected block is for nologging operation. So during a roll-forward these logs will be applied, but they will logically corrupt the affected blocks.

3. After full restore/recovery of daabase with nologging corrupted blockes you will still not see these blocks reported in v$database_block_corruption unless "VALIDATE CHECK LOGICAL DATABASE" is executed from rman to logically validate the database.

4. Nologgin corruption can not be recovered using archive logs. Because the only log recorded for nologging operations says that "This block related to nologging operation".

So if it is a table or table partition it need to be reloaded from flat file or imported from dump file. If it is a index it needs to be rebuild.

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