Re: RMAN Restore with Incremental

You are correct.... I didn't state this clearly. Sorry.

RF  

Robert G. Freeman
Author:
Oracle Database 11g New Features (Oracle Press) Portable DBA: Oracle (Oracle Press)
Oracle Database 10g New Features (Oracle Press) Oracle9i RMAN Backup and Recovery (Oracle Press) Oracle9i New Feature
Blog: http://robertgfreeman.blogspot.com (Oracle Press)

• Original Message ---- From: Jason Heinrich <jheinrichdba_at_gmail.com> To: charlottejanehammond_at_yahoo.com Cc: Robert Freeman <robertgfreeman_at_yahoo.com>; oracle-l_at_freelists.org Sent: Thursday, April 3, 2008 10:53:59 AM Subject: Re: RMAN Restore with Incremental

Charlotte,
You are correct, only the changed blocks will be backed up into the backup set. I believe Robert was referring to the fact that the entire datafile will need to be read by RMAN to determine which blocks had changed, making the backup just as slow as a full backup. Thus the importance of the BCTF to reduce time and I/O.

On Thu, Apr 3, 2008 at 11:32 AM, Charlotte Hammond <charlottejanehammond_at_yahoo.com> wrote: Hi Robert,

Can I confirm I understand correctly your remark "one block change in a datafile will cause the entire datafile to be backed up" ? If I have a (full) 4Gb datafile, say, and change a single block (eg. a single row in a table), then the whole 4Gb datafile will be backed up in a subsequent incremental level 1 backup?

This doesn't really seem to tie in to what I've seen in the past - my understanding was only that changed blocks would go into the incremental - regardless of the use of BCTF. Could you point me to the right place in the manual - please!

Thank you very much!
Charlotte

• Original Message ---- From: Robert Freeman <robertgfreeman_at_yahoo.com> To: Charlotte Hammond <charlottejanehammond_at_yahoo.com>

Sent: Thursday, April 3, 2008 2:44:38 PM Subject: Re: RMAN Restore with Incremental

The smaller backup set size could reflect a change in the underlying data, a mass delete of rows for example. Without a block change tracking file, one block change in a datafile will cause the entire datafile to be backed up in an incremental. Hense, the BCTF is pretty darned important! :-)

RF

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Jason Heinrich

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http://www.freelists.org/webpage/oracle-l Received on Thu Apr 03 2008 - 12:47:57 CDT