RMAN Read Only Tablespace

I have a 10.2.0.3 database on Solaris. I have an RMAN script that does a Hot Backup every day. It takes 9 hrs.

I was thinking about putting about 50% of the tablespaces in READ ONLY mode. The data never changes. It is part of a partitioned historical table.

After I put them in read only I take a hot backup and then the next time I add the skip readonly clause in my rman script. That is what I read.

My question is about retention. I have redundancy = 2. I am assuming it will never delete the read only tablespace backupset. Is that correct? Does anyone else use this read only skip feature?

Hi

Not answering your question directly but still here are my thoughts which might be helpful.

In my opinion

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I was thinking about putting about 50% of the tablespaces in READ ONLY mode.

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This would be a very difficult task to do.

Have you looked at Block Change Tracking in 10g and doing incremental backups ?

Also look at the documentation
http://download-uk.oracle.com/docs/c...cmconc1008.htm

for the answer to your question
regards
Hrishy

Why would that be difficult? If the data is truly read-only and the table partitions do not change, and that is true of the entire tablespace, then it should work.

Granted, BCT and incremental backups are a very useful tool to reducing backup size and times.

I am not 100% sure, but I think if you configure your retention policy to the redundancy 1(?) your will always have a backup of the read only tablespaces available.

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Originally Posted by jhmartin

If the data is truly read-only and the table partitions do not change, and that is true of the entire tablespace, then it should work.

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Most of the databases that i have come across its very difficult to isolate true read only tablespaces.

regards
Hrishy

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Originally Posted by BV1963

I am not 100% sure, but I think if you configure your retention policy to the redundancy 1(?) your will always have a backup of the read only tablespaces available.

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yes you are right if the verbatim from docs is to be beleived

from the docs

Code:

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Assume that you configure a retention policy for redundancy.
In this case, RMAN only skips backups of offline
or read-only datafiles to SBT
when there are r + 1 backups of the files,
where r is set in
CONFIGURE RETENTION POLICY TO REDUNDANCY r.

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The important aspect is to set OPTIMIZATION ON.