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Thread: Flashback coded in application?

  1. #1
    Join Date
    Oct 2002
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    807

    Flashback coded in application?

    Just curious - do any of you use applications which use flashback queries routinely? I would think it'll be a dba nightmare to manage undo on one of those systems - no?

  2. #2
    Join Date
    May 2000
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    First of all using FLASHBACK is not a DBA's job. DBA can only aid the developer to retrieve the rows which might have been deleted wrongly.

    Answering a QN in a OCP exam for the flashback is a different story.

    Tamil

  3. #3
    Join Date
    Oct 2002
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    807
    Thanks. I'm not sure you addressed my question / comment though.

    > First of all using FLASHBACK is not a DBA's job.
    Yeah right.

    > DBA can only aid the developer to retrieve the rows which might have been deleted wrongly.

    I'm not talking about using flashback to "fix" or "undo" a mistake. I was referring to using it as standard program logic within an application. My concern is about prematurely expiring undo and there by causing harakiri in the application. Yes, one has gotta size the undo / undo_retention correctly yada yada. I am aware.

    > Answering a QN in a OCP exam for the flashback is a different story.

    huh?
    Last edited by Axr2; 11-19-2004 at 05:28 PM.

  4. #4
    Join Date
    Nov 2004
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    24

    10g

    in 10g you can mange it by first setting aside how much space you want to alocate, and 2 by specifying the time interval. Say you want to be able to flashback in the last 24 hours, you can, but the trade off is using lots and lots of disk space. If you reach your threshold the DB freezes similar to Archive Logs that run out of space where they are to be kept.

    I was using the flashback table and DB features through the EM web interface for 10g and it is really quite easy, PLUS it shows you the query and lets you edit it if you want before it runs. Quite powerful stuff.

    Now if I can just get my Management server up and running on 9i and XP SP2 lol

  5. #5
    Join Date
    Oct 2002
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    Thanks for your response. I have used timebased and scn based flashback for **RECOVERY** and do know how it works etc.

    What I have NOT SEEN is - applications using flashback for periodically/systematically/programatically **COMPARING** current data with old data. Imagine a batch process that runs everynight and processes information with a "as of timestamp" or "as of scn" clause! That seems kinda scary to me. What I'd like know is - does anyone in the real world use flashback for such stuff?

  6. #6
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    Hmm I wouldnt use as application logic, I mean how can someone ensure that the undo will NEVER be overwritten?

  7. #7
    Join Date
    Oct 2002
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    807
    Originally posted by pando
    Hmm I wouldnt use as application logic, I mean how can someone ensure that the undo will NEVER be overwritten?
    Precisely my point! But the manuals indicate that FLASHBACK can indeed be used/leveraged for this purpose!!

  8. #8
    Join Date
    Nov 2004
    Posts
    24

    Flashback

    Data Recovery including FLASHBACK is the DBA's job where I am, for whoever said it wasnt.

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