So that's what happens during a restore!

I've been working with SQL Server for about 10 years now and it amazes me that I can still find little bits and pieces that I had no clue how they operated.  Today's tidbit...  The restore process.  More specifically, they events that occur when you do a restore.   Pradeep Adiga has a more detailed write up about it.

Admittedly, I thought that when you restored a database it would copy a snapshot of the database.  Turns out that's not the case.  I was about 33% correct.  There are three events that occur during a restore:

1. The data copy -- This is what most people think of when you do a restore.
2. The redo phase -- All committed  transactions in the log are rolled forward.  This includes any transactions that occurred up until the backup process has finished.
3. The undo phase -- All uncommitted  transactions in the log are rolled back.

How have I gone this long and not know this?  That being said, I've made it my goal to take at least an hour or two each week and read blogs.  Not just scan them, but really understand how things work.