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6 Replies Latest reply: Feb 22, 2013 2:25 PM by CKPT RSS

Standby Redo Log Files ?

Prashant Dixit Newbie
Currently Being Moderated
Hi Everyone,

Today after reading two different sources for Standby Protection Modes i found myself puzzled and stuck. One of the article from Burleson.com says 'Oracle supports the standby redo logs on a logical standby database and can now be configured in maximum data protection modes such as MAXIMUM PROTECTION ...'

On the other hand on some of the blogs and other resources to read, i found it something opposite to what Burleson Consulting posted on their website.
[http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG|http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG]
or
Blog from Jeff Hunter
[http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml|http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml]


Minimum Requirements for Data Protection Modes
     Maximum Protection      Maximum Availability      Maximum Performance
Redo Archival Process      LGWR      LGWR      LGWR or ARCH
Network Transmission Mode SYNC      SYNC      ASYNC when using LGWR process. Not applicable when using ARCH process.
Disk Write Option      AFFIRM      AFFIRM      NOAFFIRM
Standby Redo Logs Required?      Yes      Required for physical standby databases only (Standby redo logs are not supported for logical standby databases.)      Required for physical standby databases using the LGWR process.
Database Type      Physical only      Physical and Logical      Physical and Logical




Please help me to find true between the two.
Or please provide any doc to read.


Thanks
Prashant Dixit
  • 1. Re: Standby Redo Log Files ?
    CKPT Guru
    Currently Being Moderated
    Standby Redo Logs Required?      Yes      Required for physical standby databases only (Standby redo logs are not supported for logical standby databases.)      Required for physical standby databases using the LGWR process.
    Database Type      Physical only      Physical and Logical      Physical and Logical
    I suggest you to consult oracle documentation when it is available free. :) I hope for your question, You have to refer link http://docs.oracle.com/cd/E11882_01/server.112/e10700/create_ls.htm#i75998

    _4.1 Prerequisite Conditions for Creating a Logical Standby Database_
    Logical standby database uses standby redo logs (SRLs) for redo received from the primary database, and also writes to online redo logs (ORLs) as it applies changes to the standby database. Thus, logical standby databases often require additional ARCn processes to simultaneously archive SRLs and ORLs. Additionally, because archiving of ORLs takes precedence over archiving of SRLs, a greater number of SRLs may be needed on a logical standby during periods of very high workload.

    HTH.
  • 2. Re: Standby Redo Log Files ?
    Prashant Dixit Newbie
    Currently Being Moderated
    Thanks CKPT for replying but It seems whatever documents/URL's I've provided was created by authors considering 9i database's.
    Was this condition exists back during days of 9i (For Logical Standby)?
  • 3. Re: Standby Redo Log Files ?
    Prashant Dixit Newbie
    Currently Being Moderated
    CKPT,

    Would you like to provide me a new chart for 'Minimum Requirements for Data Protection Modes' ...



    Maximum Protection Maximum Availability Maximum Performance
    ------------------------------------------- -------------------------------------------- --------------------------------------------------
    Redo Archival Process ? ? ?
    Network Transmission Mode ? ? ?
    Disk Write Option ? ? ?
    Standby Redo Logs Required? ? ? ?
    Database Type ? ? ?



    Thanks for your time CKPT :)


    - Prashant Dixit
  • 4. Re: Standby Redo Log Files ?
    CKPT Guru
    Currently Being Moderated
    Ant ... wrote:
    Thanks CKPT for replying but It seems whatever documents/URL's I've provided was created by authors considering 9i database's.
    Was this condition exists back during days of 9i (For Logical Standby)?
    Frankly i do not have experience on 9i Oracle logical standby database.
    Dont forget that we are almost at 12c. ;)
  • 5. Re: Standby Redo Log Files ?
    Prashant Dixit Newbie
    Currently Being Moderated
    Not a problem.

    I'll really appreciate if you could help me to remove these sickles (Question Marks) below ...

    Maximum Protection Maximum Availability Maximum Performance
    Redo Archival Process ? ? ?
    Network Transmission Mode ? ? ?
    Disk Write Option ? ? ?
    Standby Redo Logs Required? ? ? ?
    Database Type ? ? ?


    Thanks
    PrashAnt
  • 6. Re: Standby Redo Log Files ?
    CKPT Guru
    Currently Being Moderated
    Maximum Protection Maximum Availability Maximum Performance
    Depends on Business requirement, By default Performance[most of the clients]
    Redo Archival Process ? ? ?
    LGWR recommended in Max performance
    Network Transmission Mode ? ? ?
    Depends. If max performance asynchronous
    Disk Write Option ? ? ?
    Not clear
    Standby Redo Logs Required? ? ? ?
    If real time apply - YES
    Database Type ? ? ?
    not clear,
    Assuming physical or logical? --Depends on requirement , Preferably Physical.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

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