How to determine whether the backup set can be recovered (note)

How to determine whether a backup set can be recovered (Note) 1. Bad blocks (1. physical blocks (2. physical damage to logical blocks: In a physical BLOCK resume uption, which is also called a media uption, the database does not recognize the block at all: 1 the checksum is invalid, 2 the block contains all zeros, 3 the header and footer of the block do not match or one of the key data block data structure is incorrect such as the data block address (DBA ). key point: the database does not recognize blocks. Features of BLOCK logic corruption: In a logical block corruption uption, the contents of the block are physically sound and pass the physical block checks; however the block can be logically inconsistent. examples of logical partition uption include partition uption of a row piece or index entry. 2. Common RMAN verification commands

-- Detect/verify the objects to be backed up. Backup Validate Check Logical BackupSpec; backup validate database; --- this will not be backed up -- Check/verify the objects to be restored. Restore Restoreobject Check Logical Validate; -- checks the backup set and the objects to be backed up. -Check Validate Backupset/Db, Ts, Df, Ctl/Spfile, archivelog {Copy} on both sides };

 

By default, only physical checks are performed on the object. If the Check Logical option is included, the system checks whether the Logical content of the object is abnormal. The difference between Restore Validate and Backup Validate. Restore restoreobject validate is to Restore the backup object from the backup set. Before that, you need to confirm whether the backup set can be read and whether the data is normal. Therefore, Oracle creates this command to check whether the backup set is damaged .. (But there is a defect. This command does not verify the archived logs, but only checks whether the Backup set can be used.) Likewise, you can understand the operation objects and functions of Backup Validate. Validate check Logical backupset includes the detection function of the Backup set and the objects to be backed up. 3. 10 Gb provides the restore preview function. restore archivelog all preview does not actually restore the archive. preview the backup set and know which backup sets and objects are required, which is equivalent to LIST. 4. note when using RMAN for recovery between different operating systems 1) Check the data dictionary and determine whether the data (endian format) of the two operating systems is the same: BIG or LITTLE. 3) after the parameter file is generated, modify the parameter file to adapt to the new system environment. 4) After the control file is mounted, modify the path of the log file to adapt to the new system environment. 5) modify the path of the data file, restore the database, and open resetlogs.