Forum OpenACS Development: Re: Some thoughts with respect to the permissions system
While I don't have any real-world stats for that, those are essentially linear relationships. Given the indexes on the table, this means we have a log2(N) join cost on something that scales by some combination of linear factors.
So I don't think there's a LOT to gain in scalability from getting rid of the inheritance tree, moving to a simple inherit-from-one-object-only paradigm.
Of course in all our work with denormalized tables we're assuming that space is relatively unimportant. With hobbyists being able to build servers with 4GB RAM thus far I think we're on pretty safe ground making this assumption. I did worry about this a bit when I introduced the acs_object_party_privilege_map but as mentioned above, thus far for real sites it's been OK to eat the space.