Subject: Re: [Policy] condition evaluation order

From: "Robert Moore" <[email-masked]>
Date: Fri, 15 Feb 2002 07:24:23 -0500

Mircea,

Way back at the beginning of the Policy work, we discussed
this exact point.  (I don't remember now whether we did
this wearing our IETF hats or our DMTF hats, but it doesn't
really matter.)  We decided that rather than putting
something into the model to let the Policy Administrator
indicate an order for condition evaluation, we would leave
it up to each PEP (or PDP) to optimize its own order for
condition evaluation.  We recognized that there would be
some cases where the Policy Administrator would have been
able to help the PEP / PDP with this optimization, by
providing it with a recommended ordering based on information
that it did not have.  But we decided that on balance there
weren't going to be enough of these cases to justify the
additional complexity in the model.  There was also concern
about cases where the Policy Administrator might specify an
evaluation order which, because of the way it was implemented,
a particular PEP / PDP would be unable to honor.

Regards,
Bob

Bob Moore
Advanced Design and Technology
Application Integration Middleware Division
IBM Software Group
+1-919-254-4436
[email-masked]