[rt-users] deleting data

[Gordon Messmer]

We're currently running RT 3.6.0.  For quite a while, we had a mail 
gateway running that allowed a whole lot of spam into the database.  
I've put up a mail filter so that only local users can email RT, now, 
and I'd like to clean up the database some.

I've used rtx-shredder to remove all of the deleted tickets.  At this 
point, though, I'm not sure how to delete users that aren't associated 
with any tickets (spam addresses).  I'm also confused about the size of 
some of the tables.  I've attached a row count from all of the tables.  
rtx-shredder doesn't seem to help cleaning some of them out.

Can anyone guess why there are several times more groups than users?  
Why is the CachedGroupMembers table so large?  Can the 
CachedGroupMembers and sessions tables be cleared entirely?  Where else 
can I look at cleaning up?

ACL :: 333
Attachments :: 61741
Attributes :: 7
CachedGroupMembers :: 227942
CustomFieldValues :: 0
CustomFields :: 0
GroupMembers :: 79256
Groups :: 83990
Links :: 295
ObjectCustomFieldValues :: 0
ObjectCustomFields :: 0
Principals :: 98550
Queues :: 16
ScripActions :: 17
ScripConditions :: 10
Scrips :: 26
Templates :: 14
Tickets :: 17338
Transactions :: 116876
Users :: 14559
sessions :: 13552