Shrinking Databases
SQL Server 2000 autoshrinks databases that have a large amount of free space. Only those databases where the autoshrink option has been set to true are candidates for this process. The server checks the space usage in each database periodically. If a database is found with a lot of empty space and it has the autoshrink option set to true, SQL Server reduces the size of the files in the database. You can also use SQL Server Enterprise Manager or the DBCC SHRINKDATABASE and DBCC SHRINKFILE statements to shrink the files of a database manually.
Files are always shrunk from the end. For example, if you have a 5 GB file and specify 4GB as the target_size in a DBCC SHRINKDB statement, SQL Server will free as much space as it can from the last 1 GB of the file. If there are used pages in the part of the file being released, SQL Server first relocates the pages to the part being retained. You can only shrink a database to the point where it has no free space remaining. For example, if a 5GB database has 4 GB of data and you specify 3 GB as the target_size of a DBCC SHRINKDATABASE statement, only 1 GB will be freed.
If a DBCC SHRINKDATABASE or DBCC SHRINKFILE statement cannot reclaim all the space in a log file, the statement will issue an informational message indicating what action you must perform to make more space eligible to be freed. For more information about shrinking log files, see Shrinking the Transaction Log.