Log In

Come Join Us!

Are you a
Computer / IT professional?
Join Tek-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Tek-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Data Migration - Rollback segments

Data Migration - Rollback segments

Data Migration - Rollback segments

Does anybody know how to find out how large a transaction will be before the transaction occurs?
I am currently working with a team that is migating data from one system to another. The originating environment is Oracle 7x and the destination is Oracle 8x. I have set up different rollback segments and corresponding tablespaces. The problem is I have no Idea what the size of the various transactions will be. In some cases they will be small (insert statements) and in others they will be large(update statements). I know I can select the rollback segment for each transaction, but I need to know the size of the transaction to know which rollback seg to assign. Any help will be appreciated.

RE: Data Migration - Rollback segments

The simplest way to handle it is to create one large rollback segment for data migration. Then turn off all the normal rollback segment (offline) and leave only the big rollback segment online. Therefore, all the transactions will use the large rollback segment and you won't have any problem.

Once you finish with the migration, you can then change all the normal rollback segment online and then drop or turn off the big rollback segment.


RE: Data Migration - Rollback segments

As Mikeleung Pointed out the best way is to online only 1 rollback segment so that the transaction may use that rollback segment. The size of each transaction can be known from the column - WRITES in V$ROLLSTAT view, by noting down the values before and after the transaction

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Tek-Tips Forums free from inappropriate posts.
The Tek-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Tek-Tips forums is a member-only feature.

Click Here to join Tek-Tips and talk with other members! Already a Member? Login

Close Box

Join Tek-Tips® Today!

Join your peers on the Internet's largest technical computer professional community.
It's easy to join and it's free.

Here's Why Members Love Tek-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close