RE: RMAN backup size is almost bigger twice than all of tablespace used size?
Date: Thu, 16 Nov 2023 08:55:42 +0000
Message-ID: <PR1P264MB1824964FF4ABABD3DF572C73F6B0A_at_PR1P264MB1824.FRAP264.PROD.OUTLOOK.COM>
Hey,
I'm sorry, but indeed Jonathan is right. I missed this change between 10.1 and 10.2, where Oracle no longer takes unused blocks into rman backup. Maybe I've been working on Oracle for too long time, since V5 ;).
So for your case, another possibility is that some files are OFFLINE. V$DATAFILE or DBA_DATA_FILES don't show offline datafile, but RMAN take them into backupset, unless you add "SKIP OFFLINE" into your backup command.
Maybe a clue 😉
Pierre
Thanks for the responses with Stefan, Pierre, Jonathan and Mladen.
Tablespace used size is calculated by the sum(bytes) of total file sizes - sum(bytes) of dba_free_space.
The compression_ratio is 1 from v$backup_set_details.
The archived logs with rman backup is only 20 gb.
Even if no compressed my rman backup I thinks shoule be only 600gb but actually 1280gb, so strange!
Best Regards
Mladen Gogala <gogala.mladen_at_gmail.com<mailto:gogala.mladen_at_gmail.com>> 于2023年11月16日周四 09:17写道：
On 11/15/23 10:17, Quanwen Zhao wrote:
Sorry, I forget to mention my RMAN backup is no compression and I've checked all of the backup sets by v$backup_set_details that has a column compressed. BTW the Archived Log has just only 20 GB, so the datafile of rman backup is only 1300 - 20 = 1280 GB, 1280 >> 600 ?
Best Regards
How many archive logs did you back up? RMAN doesn't backup just data files, if I remember correctly. Some of the databases that I am working with use 4GB redo logs. Few hundreds of those can really mess up your space, so that you can enjoy your ORA-00257 in the middle of the night. And the bad news is that archive logs typically do not compress well.
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De : oracle-l-bounce_at_freelists.org <oracle-l-bounce_at_freelists.org> de la part de Quanwen Zhao <quanwenzhao_at_gmail.com>
Envoyé : jeudi 16 novembre 2023 07:21
À : gogala.mladen_at_gmail.com <gogala.mladen_at_gmail.com>
Cc : oracle-l_at_freelists.org <oracle-l_at_freelists.org>
Objet : Re: RMAN backup size is almost bigger twice than all of tablespace used size?
Quanwen Zhao
Hello Stefan,
Quanwen Zhao
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
https://dbwhisperer.wordpress.com
http://www.freelists.org/webpage/oracle-l
Received on Thu Nov 16 2023 - 09:55:42 CET