PT3 or Postfresql hogging disk space unnecessarily?

[diggingdeeply]

It seems that PT3 or Postgresql may not be freeing space on my harddrive after it's no longer needed.
I refer to two possible situations:
1. When I delete--not remove, but delete--a database in PT3.
2. When I backup a database in Pokertracker. I notice that a large chunk of space is needed temporarily to do a backup. It seems to me that, afterwards, available space on my harddrive decreases by a lot more than the size of the final backup file.

Is there a way I can search for and free any disk space either program might be holding on to unnecessarily?

[kraada]

The Vacuum portion of Housekeeping should return all space to you.