RE: RMAN backup size is almost bigger twice than all of tablespace used size?

From: Pierre Labrousse <Pierre.Labrousse_at_digora.com>
Date: Wed, 15 Nov 2023 15:17:13 +0000
Message-ID: <PR1P264MB18247687600D0334EFB6A79AF6B1A_at_PR1P264MB1824.FRAP264.PROD.OUTLOOK.COM>

Hey,

Rman only takes into account formatted blocks and not blocks never used, so if you drop or truncate a table its blocks are considered formatted and take into backupset even blocks are empty, this generally explains the size difference

Best.

Pierre LABROUSSE
Consultant DBA ORACLE (OCM 10g/11g/12c)
Mobile +33 (0)7 56 05 27 38
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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 : mercredi 15 novembre 2023 15:14 À : ORACLE-L <oracle-l_at_freelists.org> Objet : RMAN backup size is almost bigger twice than all of tablespace used size?

Hello everyone!

Recenty I've notice that there has oracle product system with 19.13, RMAN backup size is almost bigger twice than all of tablespace used size?

Such as, all of tablespace used size is 600 GB and total size is 2500 GB, RMAN backup size (generated backup sets) is 1300 GB.

Generally speaking, RMAN backup size is almost equal to all of tablespace used size.

Firstly I suspect oracle recyclebin has occupied the massive data but the parameter recyclebin is off.

Now I have to infer business tablespace has produced plenty of table fragments or HWM (High Water Mask) or discontinuous free data blocks.

How to troubleshoot it for me? Any suggestion would be very appreciated!

Best Regards
Quanwen Zhao

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Received on Wed Nov 15 2023 - 16:17:13 CET