Zodb

Each time you delete a web page, a copy is kept in the database in case you need to get it back later. Over time, the number of unused objects can grow and grow, expanding the memory needed to operate the website, and slowing down operations...

I was resistant at first also. When I first picked up Zope in 1998, the first thing I asked was if I could store all of my data in MySQL. I didn't know what I was missing yet, but I'm glad it only took me one project to realize the true strength of using a Object Oriented Database with an Object Oriented application server...