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4 Replies Latest reply: Nov 14, 2012 4:57 AM by CKPT RSS

SYNC and ASYNC for Physical Standby DB's

Arun Natarajan-OC Explorer
Currently Being Moderated
Dear Friends,

In 11g databgurad ,

I planned to used 2 physical standy once in the same LAN and another in the DR site

I need to have SYNC between primary and Standby 1 which is in same LAN

I need to have ASYNC between primary an standy 2 which is in DR site

Is it possible , if so how do i achieve this?


Because i believe SYNC and ASYNC will be decided by oracle internally based on the Protection mode we choose so in that case

we can't have mix up (SYNC and ASYNC) for standby databases?

Regards,
DB
  • 1. Re: SYNC and ASYNC for Physical Standby DB's
    JohnWatson Guru
    Currently Being Moderated
    Protection mode is an attribute of the database. SYNC/ASYNC is an attribute of the log_archive_dest_n instance parameters, so set them individually as you require.
  • 2. Re: SYNC and ASYNC for Physical Standby DB's
    CKPT Guru
    Currently Being Moderated
    839396 wrote:
    Dear Friends,

    In 11g databgurad ,

    I planned to used 2 physical standy once in the same LAN and another in the DR site

    I need to have SYNC between primary and Standby 1 which is in same LAN

    I need to have ASYNC between primary an standy 2 which is in DR site

    Is it possible , if so how do i achieve this?


    Because i believe SYNC and ASYNC will be decided by oracle internally based on the Protection mode we choose so in that case

    we can't have mix up (SYNC and ASYNC) for standby databases?

    Regards,
    DB
    I think John already mentioned how to do, let me derive more .

    SQL> alter system set log_archive_dest_2='SERVICE=same_lan SYNC NOAFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=<db_unique_name>'
    SQL> alter system set log_archive_dest_3='SERVICE=DR ASYNC NOAFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=<db_unique_name>'

    >
         839396      
         Newbie
         
    Handle:      839396
    Status Level:      Newbie
    Registered:      Feb 23, 2011
    Total Posts:      14
    Total Questions:      8 (8 unresolved)
    >

    why all the questions are unanswered? Please close the threads and keep the forum clean. https://forums.oracle.com/forums/ann.jspa?annID=718
  • 3. Re: SYNC and ASYNC for Physical Standby DB's
    UweHesse Expert
    Currently Being Moderated
    There's a little mistake in the log_archive_dest_2 part:

    >
    SQL> alter system set log_archive_dest_2='SERVICE=same_lan SYNC NOAFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=<db_unique_name>'
    >

    instead it should be SYNC AFFIRM

    Furthermore, with the usage of DG Broker, that whole log_archive_dest_2 setting is done automatically when you just specify LogXptMode=SYNC for the first standby - it will especially avoid the above mistake :)

    Kind regards
    Uwe Hesse

    "Don't believe it, test it"
    http://uhesse.com
  • 4. Re: SYNC and ASYNC for Physical Standby DB's
    CKPT Guru
    Currently Being Moderated
    Uwe Hesse wrote:
    There's a little mistake in the log_archive_dest_2 part:

    >
    SQL> alter system set log_archive_dest_2='SERVICE=same_lan SYNC NOAFFIRM VALID_FOR=(ONLINE_LOGFILES,PRIMARY_ROLE) DB_UNIQUE_NAME=<db_unique_name>'
    >

    instead it should be SYNC AFFIRM

    Furthermore, with the usage of DG Broker, that whole log_archive_dest_2 setting is done automatically when you just specify LogXptMode=SYNC for the first standby - it will especially avoid the above mistake :)

    Kind regards
    Uwe Hesse

    "Don't believe it, test it"
    http://uhesse.com
    Uwe,

    Somewhere wrong. Thanks for correcting,
    Revising, for LGWR SYNC --> AFFIRM, ASYNC --> NOAFFIRM and however in ASYNC AFFIRM, affirm will be ignored because of asynchronous mode.

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