[ur-wg] Concall tomorrow

[Donal K. Fellows]

Stephen M Pickles wrote:
> In the strawman, we would be allowed to construct a
> document containing a compound usage record
> which itself contains a sequence of compound usage records,
> each of which comprises two atomic usage records,
> containing e.g. (1) some usage information about a compute
> job, and (2) usage information about an associated network
> reservation. As I understand it, Matt's question pertained
> not to the identity of the agent producing the record,
> nor to the identity of the ultimate end-user, but rather
> to how to identify the intermediate compound record as
> being about compute+network usage.

OK. I think I understand. That's something that the CompoundUR does not
try to tackle at all. The CUR definition makes no assertions at all
about the meaning of the compound; they're together because someone or
something thinks they should be together. However, I believe it would be
possible (maybe after a bit more schema hacking) to further subclass the
CUR to get a kind of compound UR that defines what the compound means,
which is not a problem at all from my perspective, or failing that, the
extra meaning could be attached to the CUR through its extensibility
support. I'm not stating which is preferred, and I can see reasons for
doing things both ways. (Subclassing allows for better enforcement of
any extra rules, extending is easier to make interoperable, even if not
in a necessarily useful way.)

> I think what this comes down to is that the atomic usage
> records might need to be more strongly typed.

More types of UsageRecord (e.g., SRMUsageRecord, NetworkLinkUR)?
That's fine with me, except for the actual matter of really writing
them. At that point, my laziness takes over. :-)

Donal.