Home » RDBMS Server » Backup & Recovery » RMAN Backup (10.2.0.2,Solaris)
RMAN Backup [message #488736] Mon, 10 January 2011 18:33 Go to next message
varunvir
Messages: 363
Registered: November 2007
Senior Member
Hi Experts,
I have one table space which has size of 4g which
contains table sized 2g.
If I delete all contents from the table with delete
command then what would be the sizee of
RMAN backup .
Regards,
Varun Punj,
Re: RMAN Backup [message #488749 is a reply to message #488736] Mon, 10 January 2011 23:23 Go to previous messageGo to next message
Michel Cadot
Messages: 67769
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
At least 2 gb.

Regards
Michel
Re: RMAN Backup [message #488849 is a reply to message #488749] Tue, 11 January 2011 12:19 Go to previous messageGo to next message
varunvir
Messages: 363
Registered: November 2007
Senior Member
Hi Michel,
Is it because of HWM??
Re: RMAN Backup [message #488851 is a reply to message #488849] Tue, 11 January 2011 12:32 Go to previous messageGo to next message
Michel Cadot
Messages: 67769
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Yes.

Regards
Michel
Re: RMAN Backup [message #488852 is a reply to message #488849] Tue, 11 January 2011 12:32 Go to previous messageGo to next message
BlackSwan
Messages: 26759
Registered: January 2009
Location: SoCal
Senior Member
>Is it because of HWM??
yes
Re: RMAN Backup [message #490078 is a reply to message #488736] Thu, 20 January 2011 20:26 Go to previous messageGo to next message
ebrian
Messages: 2794
Registered: April 2006
Senior Member
Your backupsets could be smaller if the following conditions are met (Unused Block Compression Of Datafile Backups to Backup Sets).

Caveat though, there were some initial problems with this even in 10.2.

[Updated on: Sat, 22 January 2011 11:45]

Report message to a moderator

Re: RMAN Backup [message #490277 is a reply to message #488736] Sun, 23 January 2011 10:15 Go to previous messageGo to next message
yogeshsi
Messages: 2
Registered: January 2011
Location: Pune
Junior Member

Its true that if u delete all rows of your Table and then take Backup.. Backup size will be 2GB .. Since HWM don;t come down when u delete any rows .. its Better to Truncate the Table than Deleting all rows ... then your HWM will be at minimum level....

You can also Consider Exporting and Importing a Segment(table) ... when we do an Import ,the table will have only one extent.
The rows will have new physical addresses and
the high watermark will be adjusted.

any more questions on this will be appreciated Cool

Re: RMAN Backup [message #490282 is a reply to message #490277] Sun, 23 January 2011 11:46 Go to previous messageGo to next message
Michel Cadot
Messages: 67769
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
1/ Please read OraFAQ Forum Guide, use plain english and don't use IM/SMS speak nor telegram style (like multiple useless dots).

2/
Quote:
its Better to Truncate the Table than Deleting all rows ... then your HWM will be at minimum level....

This changes SEGMENT HWM and not FILE HWM which is important for backup, the first one is irrelevant for this; don't mix up both.

3/
Quote:
You can also Consider Exporting and Importing a Segment(table) ...

This is NOT a database backup and is irrelevant to the question.

4/
Quote:
when we do an Import ,the table will have only one extent.

Only if 1) you use COMPRESS=Y and 2) you don't use LMT (Locally Managed Tablespace) which is a bad thing. In addition, you can fail to import due to a segment extend too large for targer database. Don't use it.

5/
Any more answers on this will be appreciated to fix false knowledge. Cool

Regards
Michel

[Updated on: Sun, 23 January 2011 11:47]

Report message to a moderator

Re: RMAN Backup [message #490285 is a reply to message #490277] Sun, 23 January 2011 12:47 Go to previous messageGo to next message
ebrian
Messages: 2794
Registered: April 2006
Senior Member
@yogeshsi...You registered for the site to post your erroneous commentary?

To add to what Michel already dispelled of your ramblings:

yogeshsi wrote on Sun, 23 January 2011 11:15
Its true that if u delete all rows of your Table and then take Backup.. Backup size will be 2GB

You apparently didn't take the time to read the other posts, if you had you would realize that the backup COULD be smaller that what it was originally as explained in the link posted above.

A truncate is not always possible for a situation, so you can NOT blindly say:

yogeshsi wrote on Sun, 23 January 2011 11:15

its Better to Truncate the Table than Deleting all rows

Re: RMAN Backup [message #490294 is a reply to message #490282] Sun, 23 January 2011 20:28 Go to previous messageGo to next message
yogeshsi
Messages: 2
Registered: January 2011
Location: Pune
Junior Member

Guys ... this was my first Post .. and yes i think i goofed up a Bit . but all i wanted was to Answer the question ... Thanks for Your Comments and Suggestions ...
Re: RMAN Backup [message #490314 is a reply to message #490294] Sun, 23 January 2011 23:18 Go to previous message
Michel Cadot
Messages: 67769
Registered: March 2007
Location: Nanterre, France, http://...
Senior Member
Account Moderator
Yes ... and ... we appreciate ... but ... follow ... the guide ... and ... take care of ... what we say ...

Regards
Michel
Previous Topic: Incremental Level Backup
Next Topic: Oracle Database recover using reset archivelogs
Goto Forum:
  


Current Time: Sun Mar 07 21:30:53 CST 2021