Re: How to validate RMAN backup

From: Mladen Gogala <gogala_at_sbcglobal.net>
Date: Wed, 24 May 2006 21:44:18 -0400
Message-Id: <1148521458l.3413l.1l@medo.noip.com>

On 05/24/2006 09:32:31 PM, Mladen Gogala wrote:

> Personally, I prefer "validate backup <pkey>" as it is much faster,

This was, obviously, my personal impression and, quite possibly, a senior moment. I tested the difference in speed and here are the results:

RMAN> validate backupset 18;

using channel ORA_DISK_1

channel ORA_DISK_1: starting validation of datafile backupset
channel ORA_DISK_1: reading from backup piece /data/orabck/backup/dbs0jhjtdbf_1_1.bak
channel ORA_DISK_1: restored backup piece 1

piece handle=/data/orabck/backup/dbs0jhjtdbf_1_1.bak tag=TAG20060524T212359 channel ORA_DISK_1: validation complete, elapsed time: 00:00:46

RMAN> restore database validate;

Starting restore at 24-MAY-06
using channel ORA_DISK_1

channel ORA_DISK_1: starting validation of datafile backupset
channel ORA_DISK_1: reading from backup piece /data/orabck/backup/dbs0jhjtdbf_1_1.bak
channel ORA_DISK_1: restored backup piece 1

piece handle=/data/orabck/backup/dbs0jhjtdbf_1_1.bak tag=TAG20060524T212359 channel ORA_DISK_1: validation complete, elapsed time: 00:00:47 Finished restore at 24-MAY-06

The "validate backupset" command took 46 seconds and "restore validate" took 47 seconds. Not even the most biased person would call that a significant difference. I somehow remember an old test,performed some time ago, without such pesky stuff as precise time measurement, that "validate backupset" seemed faster. Eventually, "RESTORE VALIDATE" was chosen for being so easy to script and always hitting the right backup, without the need for the backup number. I have to go and buy some ginkgo biloba.

-- 
Mladen Gogala
http://www.mgogala.com

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http://www.freelists.org/webpage/oracle-l

Received on Wed May 24 2006 - 20:44:18 CDT