Re: Restore/Duplicate takes a lot longer to restore than backup
Date: Wed, 6 Jan 2010 14:12:30 -0600 (CST)
Depending upon the version/release/patch level of your Oracle software, the number of channels you can dedicate to the process, and the mix of jobs running, there is a great variance in recovery time.
Things improved greatly from 10.2.0.1 to 10.2.0.3, and there are some good patches dealing with decompression in 10.2.0.4.
There are also new options to speed up recovery times by varying compression algorithms in 11g, but alas, a compressed backupset will always take longer to recover because of the extra steps involved.
- Original Message ----- From: "Howard Latham" <howard.latham_at_gmail.com> To: JBECKSTROM_at_gcrta.org Cc: "oracle-l-freelists" <oracle-l_at_freelists.org>, "oracle-db-l" <oracle-db-l_at_groups.ittoolbox.com> Sent: Wednesday, January 6, 2010 1:53:51 PM GMT -06:00 US/Canada Central Subject: Re: Restore/Duplicate takes a lot longer to restore than backup
We have found that the compression causes the restore to take MUCH MUCH MUCH longer. It seems that the decompression algorithm is very slow. WE abandoned compression so we could get a database back quicker - 3 hours instead of 18.
On 06/01/2010, Jeffrey Beckstrom <JBECKSTROM_at_gcrta.org> wrote:
> We are doing a compressed backup of a 200G database in about 2 hours. When
> we run the duplicate command, we copy the production backup files to the
> local disks of the target server. We then run the RMAN duplicate command
> and it takes over 6 hours. Is it reasonable that a restore/duplicate from a
> compressed backup takes that much longer than the actual backup? Is there
> anything that can be done to speed up the process?
> Jeffrey Beckstrom
> Database Administrator
> Greater Cleveland Regional Transit Authority
> 1240 W. 6th Street
> Cleveland, Ohio 44113
-- Howard A. Latham -- http://www.freelists.org/webpage/oracle-l -- Michael Fontana Sr. Technical Consultant Enkitec M: 214.912.3709 enkitec oracle_certified_partner -- http://www.freelists.org/webpage/oracle-lReceived on Wed Jan 06 2010 - 14:12:30 CST