RMAN 1.1 Types of Failure
- When a program attempts to enter invalid data into an Oracle Table.
- Long data insertion job or data import job to fail midway between there is no more room to put the data in.
- Proper privileges to perform a task.
User process Failure
- abnormal disconnect or performing a terminal program error and losing the session connection.
- DBA not much work to do here.
- BG process rollback the uncommitted transaction changes to the data and releases the locks.
Instance Failure
- Your database comes down such as Hardware , a power failure and an emergency shutdown procedure.
- An instance shutdown when the key Oracle bg process such as PMON shutdown because of an error condition.
- Check Alert log and trace files.
- Just restarting the Database instance using by STARTUP Command.
- The database was clearly shutdown and the database files aren’t synchronized.
- Oracle will perform an automatic instance or crash recovery at this point.
- Automatically perform a rollback uncommitted transactions by using the data from undo segments and roll forward committed changes it in the online redo logs.
- Don’t need to any sort of backup when restarting the database.
Network Failure
- Net listener, NIC and network connection has failed.
- DBA must configure the multiple network cards.
User Error
- Wrongly deleting data from table and dropping a table you can use FLASHBACK feature.
- If the transactions not completed yet, rollback statement.
- Oracle LOGMINER also comes on handy situation like this.
Media Failure
- It occur when you lose a disk or a disk controller fails.
- Examples of media failure i) Head crash II) File corruption III)Overwriting or deleting of a datafile.
- Any one of the multiplexed control files are deleted or lost because of disk failure you must restore the missing control file from an existing control file.
- Datafiles, undo table space is deleted or lost because of a disk failure.If you lose one of these files, the instance may shutdown or may not sutdown in such case
sql> shutdown abort; Then
sql>startup mount
Restore the datafiles and recover it.
- An entire redo log group lost. if you have atleast one member of the redo log group , your database instance can continue to operating normally.
- Restore the log file by copying one of the other members of the same group.
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