Crash recovery only requires redo from the online logs: archived redo logs are not required.
is most recent and then backs up all blocks changed since that backup.
Backup undo optimization applies to level 0 and full backups.
It is built-in RMAN behavior and cannot be disabled.
Oracle identifies corrupt blocks as either logically corrupt (an Oracle internal error) or media corrupt (the block format is not correct).
You can repair a media corrupt block with , or dropping the database object that contains the corrupt block so that its blocks are reused for another object.
crash recovery The automatic application of online redo records to a database after either a single-instance database crashes or all instances of an Oracle Real Applications Cluster configuration crash.
If you closed the database consistently, then all the files in the backup are consistent. Unless you apply the redo generated since the consistent backup was created, however, you lose all transactions since the time of the consistent backup.
You can only take consistent backups after you have performed a mode, after structural changes.
After the LGWR process fills each online redo log with redo records, the archiver process copies the log to one or more redo log archiving destinations. RMAN does not distinguish between an original archived redo log and an image copy of an archived redo log; both are considered image copies.
archived redo log failover An RMAN feature that enables RMAN to complete a backup even when some archived log destinations are missing logs or have logs with corrupt blocks.