[UPS] Dienst protocol: Partitions and partitionspecs

[Robert Tansley]

Hi, I'm currently add open archive support to CogPrints/EPrints. I'm
using the open archives subset of the Cornell Dienst software for this,
which I hope we can distribute with our EPrints software when it's
released; however that should be the subject of another email. This is a
more technical question.

Referring to
http://www.cs.cornell.edu/cdlrg/dienst/protocols/OpenArchivesDienst.htm:

I'm unclear about partitionspecs, particularly in relation to the List
Contents verb. From the grammar given in section 2.2.1, it appears that a
partitionspec consists of 1 or more partition names. The example given,
"Florida;Frenetics" is rather ambiguous. Does this refer to two
partitions, "Valley View University of Florida" and "Department of
Frenetics"? i.e. If this is sent as part of a List Contents request, do I
return documents in "Valley View University of Florida" and documents in
"Department of Frenetics" partitions?

Or, does that partitionspec refer to the single partition "Department of
Frenetics", with the "Florida;" part just specifying the ancestry in the
hierarchy? In which case, since the example seems to pertain to the
hierarchy given in section 2.2, surely it should include the Institutions
node in the hierarchy, to become something like
"Institutions;Florida;Frenetics"?

The example in the description of the List Contents verb,
"partitionspec=physics;hep" seems to suggest the latter, which would mean
that a partitionspec can only be used to specify a single partition. Is
this correct?

If so, this does give rise to another ambiguity. If, using the arXiv
example, I were to send a List Contents request with
"partitionspec=physics", does that implicitly include "physics;hep",
"physics;ex", "physics;lat" etc.? Or, is there an assumption that actual
documents will only be stored in the "leaves" of the partition hierarchy,
so you should only ever specify leaves in a partitionspec?

Although the CogPrints incarnation of our software has a two-level
hierarchy, with all documents held at the leaves, the core software
doesn't enforce that. How the hierarchy works is up to the individual
site configuration. Thus you could easily end up with an archive in which
some documents are held at, say, "Southampton;ECS", and some at
"Southampton;ECS;IAM". In which case, does the partitionspec
"Southampton;ECS" include documents in "Southampton;ECS;IAM" as well?
(i.e. Would a List Contents request with "partitionspec=Southampton;ECS"
respond with the documents from the IAM partition too?)

Maybe I haven't understood the Dienst document fully, but I could really
do with some clarification on these points.

Thanks

R

-- 
 Robert Tansley                    Tel: +44 (0) 23 80594492
 Multimedia Research Group         Fax: +44 (0) 23 80592865
 Electronics & Computer Science    http://www.ecs.soton.ac.uk/~rht96r/
 University of Southampton
 Southampton SO17 1BJ, UK