I've been running some utilities from one of our vendors to purge older data. Their recommendation is to run these utilities and then to create/run the index rebuild maintenance plan, which I did. We're running SQL Server 2008 Enterprise and I set the maintenance plan to sort in tempdb an dto keep the index online. It took about 4 hours to run and when completed, my 30GB mdf file turned into about 80GB. This freaked me out and I shrank the database, knowing that this would basically undo the reindex process. The shrink didn't bring me back to the original 30GB. I ran the maintenance plan again and my mdf file jumped up to 170GB. How is it that this happens and that I can't reclaim the free space? Shouldn't the original indexes be removed when the new one comes online? One thing to note is that the original fill factor was 100%, which I changed to 90. I can't imagine this being the result of going from 30 to 170GB. I won't be running the maintenance plan again and have also disabled it. Disk space is a huge concern in this particular case, but rather the effects this might have on my system's performance. Any ideas and help would be greatly appreciated.