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commvault oracle TDE compression


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I have a oracle database with TDE enabled and it is giving poor compression during backups.

As per below url, rman compression needs to be disabled on the client. Where can i find this setting?

https://documentation.commvault.com/commvault/v11/article?p=20811.htm

 

Thanks

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Best answer by Mike Struening 15 June 2021, 20:19

@Sandy11 , saw the incident closed out with the update that you switched to RMAN compression.  I’ll mark this as solved.

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@Sandy11 , 

The setting is at the rman level. You need to check rman #show all; output and see if compression enabled at the oracle/client level.


Please check the following oracle document for more details:-

https://docs.oracle.com/cd/E11882_01/backup.112/e10642/rcmconfa.htm#CHDEHCEB

 

If you find any parameter like "configure compression algorithm" with Basic, Low, Medium, or high, that means the compression has been enabled at the client/oracle level.

Please let me know in case of any questions.


 

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Thanks. So the recommended setting for Oracle with TDE configured will be:-

CONFIGURE COMPRESSION ALGORITHM 'NONE';

 

Is that correct?

 

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@Sandy11 , you can leave that setting to BASIC or default.


Example:-
CONFIGURE COMPRESSION ALGORITHM ‘BASIC’;

But don’t use a compress command in the rman backup scripts.
If the backup runs through commvault GUI, by default, the backup command won’t add use compression unless you run a specific script that has compress command with a custom script option.
 
Please let me know in case of any questions.

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Great, thanks for the clarification, @Mahender Reddy . Currently we are not using any custom scripts. Backup is schedule through GUI. We are seeing less than 2% compression. What is the typical compression seen with TDE enabled databases? 

DBA is claiming that they can get much better compression than this using RMAN. So we are going to test that out with rman compression this weekend.

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@Sandy11 , We don’t have a baseline for an expected compression ratio with TDE. It depends on the nature of the data. Please let me know how much savings you got with Oracle compression. I will check internally based on the results.

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Hi @Sandy11 !  Were you able to implement @Mahender Reddy ‘s settings and check the compression savings?

Thanks!

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@Mahender Reddy We tested a TDE enabled database backup once using commvault compression/deduplication and then second time using rman compression.

Database size - 500 GB

Using commvault deduplication/compression - Backup size - 121 GB

Using RMAN compression - Backup size - 109 GB.

 

 

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@Sandy11.  thanks for the reply!  Spoke to Mahender and some internal folks who suggested you open a case and share the logs of a GUI job.  the number of factors in this case are too complex for a forum thread, though we can share the eventual solution back here for posterity.

Can you open a case and share the case number with me?

Thanks!

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I opened a case for this three weeks ago. I have sent you the case number via private message. Thanks

 

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Appreciate it, @Sandy11 !  I see that you are working with superstar Russ.  I’ll keep an eye out.

Userlevel 7
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@Sandy11 , saw the incident closed out with the update that you switched to RMAN compression.  I’ll mark this as solved.

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