SQL Server Recovery–MCM Prep

I always have to think about what happens during the recovery process in SQL Server after a restore. I’ve always known the process as roll forward and roll back, which is how the items are noted in the SQL Serve error log. Transactions are rolled forward or rolled back.

But which comes first?

If you think about it, you want to roll forward the committed transactions, which were not written to the data files. Then you roll back the changes made to the data files which were not committed. How you get transactions in these states is for another day.

However I found an easier way to remember. While studying for the MCM, I heard these processes referred to as redo and undo, which apply to roll forward and roll back, respectively. If you use these terms and place them in alphabetical order, you get redo, undo.

Or redo before undo.

About way0utwest

Editor, SQLServerCentral
This entry was posted in Blog and tagged , , . Bookmark the permalink.

1 Response to SQL Server Recovery–MCM Prep

  1. Pingback: #2 Skill – Performing a Restore « Voice of the DBA

Comments are closed.