human readable?redo log,roll back segment,archive
DBAsupport.com Forums - Powered by vBulletin
Results 1 to 4 of 4

Thread: human readable?redo log,roll back segment,archive

  1. #1
    Join Date
    Jun 2006
    Posts
    101

    human readable?redo log,roll back segment,archive

    1.are data in redo log file, archive logs,undo tbs ,rollback segment are human readable?

    2. what happens to the data within rollback segment,undo tbs after some period of time ?will they be permanetly deleted? or are included in archive logfile?for point in time recovery?

    3. does archive log include DDL? if not then what will happen if we delete all data from tbl1 on monday, set unique constraint on the table on tuesday and on wednesday try to do incomplete recovery to mondays date ( there used to be some duplicate entry in tbl1 on monday).

    thanks
    Last edited by khoshtip_uk; 05-09-2007 at 01:12 PM.

  2. #2
    Join Date
    Sep 2002
    Location
    England
    Posts
    7,333
    1) no (unless you use log miner)
    2) removed when they arent needed

  3. #3
    Join Date
    Jun 2006
    Posts
    101
    Quote Originally Posted by davey23uk
    2) removed when they arent needed
    in this case then when we do incomplete recovery to bring database up to the point before it failed. where do we get the actual data from?

    thanks


    when i say human readable I mean whether possible to view data within it directly or using any other tool like log miner and undrestand it.

  4. #4
    Join Date
    Jun 2006
    Posts
    101
    just figured out answer for
    Q2 : rollback segment is only for read consistency and the data is not really required for roll forward. archive logs seems to contain sql (update/delte) and at the time of recovery it just applies it to the DB.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Click Here to Expand Forum to Full Width