Soft Deletion impact on server performance

Hi

I would like to know about Soft Deletions

I know how to set it up etc....
My question has to do with how it works

If i have a database that has several 1000 documents deleted each week would the overhead on the server be high
Each document would have a time stamp I would think, and then would the soft deletions be checked every hour within the time frame specified (48 hrs)to see what documents can now be permanently removed.


This could potentially be a high server use could it not.
On the otherhand if I have 1200 mail users with this feature turned on would that also be taxing on the resources to check every mail file once an hour for possible permanent deletions

Any advice or information welcome

Regards

James E Wood