Open Stack

Hello,

While digging in nova's database, I found that many objects ar not 
really deleted, but instead just marked deleted.
In fact, it's a general behavior in other projects (cinder, glance...).

I understand that. It can be handy.

But, is there a way to handle regular purging of theses elements inside 
OpenStack configuration ?

Or do we, operators, have to create batchs to purge all that ?