W3C home > Mailing lists > Public > www-zig@w3.org > February 2002

Re: SV: Z39.50 on the web (and in print)

From: Robert Sanderson <azaroth@liverpool.ac.uk>
Date: Sat, 23 Feb 2002 19:45:20 +0000 (GMT)
To: Rob Bull <bull@crxnet.com>
cc: Mike Taylor <mike@tecc.co.uk>, <www-zig@w3.org>
Message-ID: <Pine.LNX.4.33.0202231859590.5918-100000@gondolin.hist.liv.ac.uk>

> >I think most people would be happy to get something together, even if it's 
> >not Explain mapped directly into XML.
> agreed upon.  Thats why ONE-2 folks did explain lite - they have
> already done the full explain service and needed something that would

I'm sorry, but Explain Lite is simply not sufficient :(  Perhaps it might 
please some people, but I'm 100% certain that a better XML definition 
could be relatively easily agreed upon that could support better 
definitions of what Z can really do, with less confusion and better ease 
of autocreation.

> If someone [tm] were to map out an attribute architectured way of 
> searching explain like records, then you could return them in GRS1, XML, 
> SUTRS or whatever else you wanted.  Just put them into a database 
> called... iR-exPlAin-2 [1] or whatever was agreed upon.

> Not really - I am telling people about our servers in a consistent way
> that does not need a Z39.50 connection. The XML data on the web

I hear this a lot and it confuses me to no end.  Here we have a protocol 
that excels at search and retrieval, but people keep telling me that we 
shouldn't use even the basics of it for searching and retrieving records 
that describe our own databases. 

Am I the only person that doesn't understand this?  Why should a Z39.50 
client have all the vast amounts of code required to parse SOAP, when 
we've got everything already done for us using Z?!

> delivered by the Z server. Editing XML is straightforward - there are
> loads of tools out there - system administrators can understand it.
> You simply cant edit GRS, or Explain-RS records that way - the records

Err... you don't have X format databases in Z39.50, as Mike (IIRC) 
cheerily pointed out to me once.  You have a database, and the client 
requests records in whatever format it wants them in.  The server then can 
refuse to deliver them if it can't do whatever transformation it needs to.
So you like XML, that's no problem, use XML for your underlying data store
and map it into GRS1, MARC, SUTRS, or whatever else when you get requests
for those record syntaxes.

> You then don't have to worry about either taking an unnecessary hit on 
> init, or somehow connecting to a web server to get information about the 
> Z server.  Finding out where to go for the webserver is of course yet 
> another question that's unanswered -- may as well just use what we've 
> already got, eg Z39.50 databases with records in them.
> - no - I can post a registry of servers and find that on Google etc.

You the human agent can certainly do that, yes.  On the other hand a
client should definitely not have to be use a completely different
protocol, go to a search engine, parse the resulting web pages, and so

As I asked before, unless I, the human agent, knows in advance where to go
to find the XML record, how can I possibly know where to find it?  The
machine with the Z database may not have a web server.  Or it may have
more than one Z server running on it, administered by different people.  
Irwell.mimas.ac.uk for instance has at least 4 zservers running and
probably more.  If a human agent can't find it, how can a client be 
expected to?

Otherwise why use XML? Why not have instructions in plain old English (or 
other language or both) on how to configure your client?

> Probably, but you have a big project behind you who all have to use it ;)
> If you count all the Cheshire servers, then we may have you beat for 
> Explain capable machines.
> - but where are the explain capable clients to use them ?

We have one. I'm sure Sebastian has one. I expect that bell-labs has one, 
as their server has Explain and I would expect that they must have tested 
it.  I know Ashley has one, as he must have tested COPAC's explain data...
Why don't you have one as well?

http://gondolin.hist.liv.ac.uk/~cheshire/client/ has a whole slew of 
screenshots proving ours, if you want :)


      ,'/:.          Rob Sanderson (azaroth@liverpool.ac.uk)
    ,'-/::::.        http://www.o-r-g.org/~azaroth/
  ,'--/::(@)::.      Special Collections and Archives, extension 3142
,'---/::::::::::.    Twin Cathedrals:  telnet: liverpool.o-r-g.org 7777
____/:::::::::::::.              WWW:  http://liverpool.o-r-g.org:8000/
Received on Saturday, 23 February 2002 14:48:50 UTC

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