[OAI-implementers] protocol comments, OAI 2.0

[Michael L. Nelson]

>And implementors have much better things to do with their time than
>re-invent RPC.

I thought re-inventing Sun RPC is what SOAP is all about ;-)

>I would be very interested in the reasons for this. With a SOAP
>interface, it would be fairly easy to build a harvester for
>our search engine. It would be a very nice sample program for our
>indexing interface. But with a one-of-a-kind XML protocol, it isn't 
>worth the trouble.

I agree with your point about a one-off protocol.  However, as Simeon
mentioned, OAI 2.0 will not have http dependencies.  Much like DP9, we
fully expect 3rd party OAI <-> SOAP gateways to be written.  This would
make the OAI data providers available to SOAP-based crawlers.

>Different sets can be different protocol endpoints, with no loss of
>generality. Instead of respository, speak of the server which is
>providing access to the sets.

>So one server could provide these:

>  arXiv
>  arXiv-cs
>  arXiv-math
>  arXiv-physics
>  arXiv-nlin

>Or those could be spread across multiple servers.

this is still doable in OAI; the following suggests multiple strategies
that would actually be similar in implementation:

http://www.arxiv.org/oai/?verb=ListRecords&set=physics
http://www.arxiv.org/oai/?verb=ListRecords&set=math
etc.

or

http://www.arxiv.org/oai/physics/?verb=ListRecords
http://www.arxiv.org/oai/math/?verb=ListRecords
etc.

Indeed, I think time will reveal that 1 DL (or 1 organization) will desire
many OAI interfaces.


Perhaps the best description is the primary goal of keeping OAI as simple
as possible for data providers, even at the expense of service provider.
The notion is that if being a DP is as *absolutely simple* as possible,
more DPs will exist.  A critical mass of DPs will cause SPs to emerge.

I suppose this point is debatable, but I consider the OAI-PMH over http
much easier to implement than SOAP.

So, I guess the next question is "who will write the first OAI <-> SOAP
gateway?"

regards,

Michael

---
Michael L. Nelson
NASA Langley Research Center		m.l.nelson@larc.nasa.gov
MS 158, Hampton, VA 23681		http://www.ils.unc.edu/~mln/
+1 757 864 8511				+1 757 864 8342 (f)