I have executed `sp_spaceused` and get the following data: database_name database_size unallocated space test 482767.63 MB 166888.50 MB reserved data index_size unused 198876288 KB 158468464 KB 39772752 KB 635072 KB So, I have a lot of unallocated space and have read that it could be reduce by using `DBCC SHRINKFILE`. I have read that `unallocated space is space that is not reserved for use either by data or log files (Space Available)`. So, should I reduce it at first place and why it is so large?
You should always have some unallocated space within your database. Otherwise, as you need to add data, the database will have to grow the space to accommodate, slowing things down. I wouldn't suggest messing with it too much. Shrinking files can lead to serious fragmentation issues at the OS level that are not easily fixed.