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7 Replies Latest reply: May 17, 2013 2:20 PM by karan RSS

Physical standby vs Active DG

801855 Newbie
Currently Being Moderated
Oracle version :- 11gR2
OS :- Linux

We are having a 2 node RAC Primary & 2 node RAC Physical standby(not Active DG) setup configured on ASM.

Questions:-

1) Is there a way that we can convert the exsiting physical standby to Active dataguard configuration ? if yes , please post the steps.

2) If I have to build a physical standby(Active DG) from scratch what steps should i follow ? How is the Active DG setup different from regular Physical standby setup.

I am aware that active DG requires extra licensing. Thanks for your time.
  • 1. Re: Physical standby vs Active DG
    karan Pro
    Currently Being Moderated
    Active data guard means MRP will apply the changes while your database is open read only mode available for real time queries, while in physical standby it is mounted unavailable for queries thats why active data guard is expensive and has license


    To make an active data guard environment , Simply you have to create a physical standby from scratch, and then if you want to convert it to active data guard do the following

    If you are not using broker,

    cancel mrp
    SQL> recover managed standby database cancel;
    SQL> alter database open read only ;
    SQL> recover managed standby database disconnect;

    If you are using broker

    DGMGRL> edit database sby2 set state = 'APPLY_OFF';
    SQL> alter database open read only ;
    DGMGRL> edit database sby2 set state = 'APPLY_ON';

    If you want to come back to physical standby now do the following
    SQL> startup force mount

    and broker will start the MRP automatically

    If not using broker then

    SQL> startup force mount
    SQL> recover managed standby database disconnect;

    Edited by: Karan on May 18, 2013 2:01 AM
  • 2. Re: Physical standby vs Active DG
    801855 Newbie
    Currently Being Moderated
    what happens if i try to open my Physical standby database in read only mode (assuming that I dont have Active DG license)...Will it throw an error ?

    Im not using broker in this configuration.
  • 3. Re: Physical standby vs Active DG
    karan Pro
    Currently Being Moderated
    You will not be able to open it in read write mode, If you open in read only mode you are ok, but if you start mrp in read only mode it becomes active data guard
  • 4. Re: Physical standby vs Active DG
    801855 Newbie
    Currently Being Moderated
    Thanks for your time...

    So according to you even if I dont have a Active DG license I can still open the physical standby database in read-only mode , correct ?
  • 5. Re: Physical standby vs Active DG
    karan Pro
    Currently Being Moderated
    yes correct absolutely but dont start MRP :)
  • 6. Re: Physical standby vs Active DG
    801855 Newbie
    Currently Being Moderated
    Ok 1 more question...when opening in read only mode I dont have to create any restore points right ? what happens if I try to start the MRP process ?...just making sure I am doing correctly...
  • 7. Re: Physical standby vs Active DG
    karan Pro
    Currently Being Moderated
    If you start mrp in open read only mode it becomes active data guard, no need to create restore points

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