Database Shrink

Hi,

Does database shrinking require all requisites that are necessary for compacting (like additional free space and closed database) ?
And is there any programmatic way to estimate optimized database size regarding current database size, like it was done by special tool in SQL Management Studio?
The various aspcects of SQL CE database maintenance are covered here: http://msdn2.microsoft.com/en-us/library/ms172411(SQL.90).aspx There is both Compact and Autoshrink features. No tools exists for estimating space to be recovered, but you can tune Autoshrink via your connection string. Autoshrink works "automatically", and does not require closed connections or additional free space.