question

[bxr556]

when i issue
validate backupset , what did rman do to validate?
what rman validated?

[padmam]

Hi, 18th April 2001 12:24 hrs chennai

Information available in Oracle Documentation.

To examine a backup set and report whether it can be restored. RMAN scans all of the backup pieces in the specified backup sets and looks at the checksums to verify that the contents are intact so that the backup can be successfully restored if necessary. Note that validate backupset actually tests whether the backup sets can be restored, whereas change ... crosscheck merely examines the headers of the specified files.

Use this command when you suspect that one or more backup pieces in a backup set are missing or have been damaged. Use validate backupset to specify which backups to test; use the validate option of the restore command to let RMAN choose which backups to validate.

Requirements
Use this command only within the braces of a run command.

Allocate at least one channel before executing a validate backupset statement.

Keywords and Parameters
primary_key
specifies the backup sets to be validated by primary_key. Obtain the primary keys of backup sets by executing a list statement or, if you use a recovery catalog, by querying the RC_BACKUP_SET fixed view.

check logical
tests data and index blocks that pass physical corruption checks for logical corruption, e.g., corruption of a row piece or index entry. If RMAN finds logical corruption, it logs the block in the alert.log and server session trace file. The RMAN command completes and Oracle populates V$BACKUP_CORRUPTION and V$COPY_CORRUPTION with corrupt block ranges.

Note: validate does not use maxcorrupt.
====Checksum=========
Checksum is a cross verification value generated for checking any alteration or damages.

Cheers

Padmam