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If REFRESH will do the task of REWIND !! Why do we have REWIND option ?

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  • 1.  If REFRESH will do the task of REWIND !! Why do we have REWIND option ?

    Posted 04-11-2016 08:10:00 AM
    As per my  understanding if REFRESH will do the task of REWIND.

    Task : "you can choose to refresh the VDB from a snapshot or a specific point in time." 

    https://docs.delphix.com/display/DOCS40/Refreshing+a+VDB

    Why do we need REWIND option ?


  • 2.  RE: If REFRESH will do the task of REWIND !! Why do we have REWIND option ?
    Best Answer

    Posted 04-11-2016 08:17:00 AM
    Rewind and Refresh are different operations:

    REWIND: Go back to a previous point in the lifetime for that VDB.

    REFRESH: Recreate a VDB from a point in time of the parent dSource.

    When you provision a VDB, you are creating a new timeline (or branch). The difference between the operations is which timeline you use to re-provision a VDB, either the VDB's history (Rewind) or the dSource/parent's (Refresh).

    Hope that helps,

    Scott.


  • 3.  RE: If REFRESH will do the task of REWIND !! Why do we have REWIND option ?

    Posted 04-11-2016 08:24:00 AM
    Scott ,

    but w.r.t to link :  https://docs.delphix.com/display/DOCS40/Refreshing+a+VDB

    Refreshing a VDB means : 

    1) will re-provision the VDB from the dSource. As with the normal provisioning process,

    2) you can choose to refresh the VDB from a snapshot or a specific point in time.


    Point 2 : REWIND right ?  Please correct if i am wrong....

    Hence REFRESH is doing the task of REWIND !!

    Hence when you refresh a VDB, you are essentially re-setting it to the state you select during the refresh process.





  • 4.  RE: If REFRESH will do the task of REWIND !! Why do we have REWIND option ?

    Posted 04-11-2016 10:25:00 AM
    Point 2 is REFRESH.

    Refresh means: to get data from source (the other DB that originated your virtual copy)

    Rewind means: to get old data from the history of your VDB 

    Let's have a source DB called DB_1
    DB_1 -> generates a virtual copy VDB_1

    refreshing VDB_1: copy data from DB_1 to VDB_1

    rewinding VDB_1: copy data from the past of the VDB_1 to VDB_1 (is like the rewind on your old music tape).

    Hope my sample will be useful.
    Regards.
    Gianpiero


  • 5.  RE: If REFRESH will do the task of REWIND !! Why do we have REWIND option ?

    Posted 04-11-2016 10:41:00 AM
    But below statement(BOLD letter) is contradicting :

    Refreshing a VDB will re-provision the VDB from the dSource. As with the normal provisioning process, you can choose to refresh the VDB from a snapshot or a specific point in time

    link  :https://docs.delphix.com/display/DOCS40/Refreshing+a+VDB 


  • 6.  RE: If REFRESH will do the task of REWIND !! Why do we have REWIND option ?
    Best Answer

    Posted 04-11-2016 11:02:00 AM
    Rao, that is not contradictory. 

    Rewind: Go back to any point (snapshot or point in time) in time on the same time line for that VDB. ex. Restoring your current database using flashback.
    Refresh: Replace the current data in your VDB with the data from any point (snapshot or point in time) in time from another database.  ex Dropping all the data from your current database and restoring it from a backup of another database.

    Does this make sense?