RMAN Read Only Tablespace
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Thread: RMAN Read Only Tablespace

  1. #1
    Join Date
    Jan 2001
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    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?

  2. #2
    Join Date
    Jan 2001
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    Hi

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

    In my opinion
    I was thinking about putting about 50% of the tablespaces in READ ONLY mode.
    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
    Last edited by hrishy; 08-12-2008 at 10:56 AM.

  3. #3
    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.

  4. #4
    Join Date
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    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.
    One, who thinks that the other one who thinks that know and does not know, does not know either!

  5. #5
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    Quote 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.
    Most of the databases that i have come across its very difficult to isolate true read only tablespaces.

    regards
    Hrishy

  6. #6
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    Quote 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.
    yes you are right if the verbatim from docs is to be beleived

    from the docs

    Code:
    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.

  7. #7
    Join Date
    Apr 2006
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    377
    The important aspect is to set OPTIMIZATION ON.

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