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Thread: Archivelog Mode....

  1. #1
    Join Date
    Jun 2002
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    88

    Archivelog Mode....

    Dear Gurus,

    Right now my database is NOARCHIVELOG mode.In the TEST Instance weekly twice i will took backup.(Cold Backup).

    Cold Backup means purely shutdown the database.After that using the command:

    ufsdump 0ucf /dev/rmt/oh u02

    Suppose If i put my database ARCHIVELOG mode, OFFLINE backup is
    possible.(Cold Backup) or only online Backup.

    I thought once set the Archivelog mode after that cold backup is
    very difficult.

    Because the database is ONLINE (24*7) 365 days backup.

    Can u please tell me offline (Cold Backup) is possible weekly once?

    Awaiting ur reply,

    Thanks in advance,
    Iyyappan.M

  2. #2
    Join Date
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    You can take Cold backups of an ARCHIVELOG database only after you shutdown the database. It is NOT possible to take cold backup of an ARCIHVELOG database when it is open.

    The rule of thumb is:
    Cold Backup -> ARCHIVELOG is off
    Hot Backup -> ARCHIVELOG is on
    Agasimani
    OCP(10g/9i/8i/8)

  3. #3
    Join Date
    Jun 2002
    Posts
    88
    Hi,

    Thanks for ur reply.

    The rule of thumb is:
    Cold Backup -> ARCHIVELOG is off
    Hot Backup -> ARCHIVELOG is on

    As per mail ARCHIVELOG mode offline backup is not possible?

    suppose when i shutdown the database (ARCHIVELOG) mode and take offline backup. what will be do in the database.

    After finishing backup When i start the database it works fine or
    not?

    Please advise me,

    Thanks in advance,
    Iyyappan.M

  4. #4
    Join Date
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    You can ofcourse take a cold backup when ARCHIVELOG is ON by shutting down the database, but then you loose the benefits of keeping the ARCHIVELOG ON. That means you cannot make point-in-time recovery in case your database crashes.
    Agasimani
    OCP(10g/9i/8i/8)

  5. #5
    Join Date
    Oct 2002
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    391
    to turn on or off is by " alter database archivelog/noarchivelog "

    in sqlplus.

  6. #6
    Join Date
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    Location
    Singapore
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    Originally posted by agasimani
    You can ofcourse take a cold backup when ARCHIVELOG is ON by shutting down the database, but then you loose the benefits of keeping the ARCHIVELOG ON. That means you cannot make point-in-time recovery in case your database crashes.
    I didn't get it? What makes you think that Point In Time Recovery is not possible after having cold backup of a archived log database.

    In ARCHIVELOG mode you can take either cold or hot backup. Whereas NOARCHIVELOg mode doesn't allow you to take hot backup.
    Though I don't buy the idea of taking cold backup of ARCHIVELOG database, I don't think it will do any harm.
    Sanjay G.
    Oracle Certified Professional 8i, 9i.

    "The degree of normality in a database is inversely proportional to that of its DBA"

  7. #7
    Join Date
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    Hi

    You must and always take a cold back up after implementing the archive log mode for the fist time. Atleast one cold back should be there after settting the DB to archive log.

    so that while recovery it asks for the archive log files created after the initial cold backup(taken after enabling the archivelog) or else it would ask for archives generated (virtual) before enabling the archive logs.

    Cheers
    Amar
    Amar
    "There is a difference between knowing the path and walking the path."

    Amar's Blog  Get Firefox!

  8. #8
    Join Date
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    Originally posted by adewri
    You must and always take a cold back up after implementing the archive log mode for the fist time. Atleast one cold back should be there after settting the DB to archive log.

    so that while recovery it asks for the archive log files created after the initial cold backup(taken after enabling the archivelog) or else it would ask for archives generated (virtual) before enabling the archive logs.
    This of course is not true. The first sentence above should read:
    You must always take a full back up after implementing the archive log mode for the fist time.
    It doesn't have to be COLD backup, HOT backup will be perfectly OK.

    In short, I think there is not a single situation in Oracle where you are forced to take cold backup - in all situations hot backup is totaly sufficient.
    Jurij Modic
    ASCII a stupid question, get a stupid ANSI
    24 hours in a day .... 24 beer in a case .... coincidence?

  9. #9
    Join Date
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    Originally posted by jmodic
    This of course is not true. The first sentence above should read:

    It doesn't have to be COLD backup, HOT backup will be perfectly OK.

    In short, I think there is not a single situation in Oracle where you are forced to take cold backup - in all situations hot backup is totaly sufficient.
    Yep i agree, my mistake.
    not necessary to take cold backup.

    Amar
    Last edited by adewri; 01-13-2003 at 07:37 AM.
    Amar
    "There is a difference between knowing the path and walking the path."

    Amar's Blog  Get Firefox!

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