I back up my SQL Server 2005 databases daily with a SQL Server Agent job. Now I'd like to do some kind of intermediate backup, or backups, during the business day which will get saved on a remote computer every 20 minutes so we can always be sure to never lose anything other than the last 20 minutes.
I need advice. Should I set the databases to Full or Simple? Should I create transactions logs or do differential backups? I'm not entirely sure how transaction logs work. Do they journalize each transaction? What is this business about having to clean up log space, and "expiration"?