Re: Why Z39.50 will not work for DASL

At 17:49 29-01-99 -0800, Jim Davis wrote:

>My objection to Z39.50 is based on the inflexiblity of the Type-1 query.
>In this query, one may provide up to six 'attributes':
>  * use (which is similar to a DAV property)
>  * structure (which is somewhat like a datatype)
>  * relation  which is like a DASL comparison operator)
>  * truncation 
>  * position 
>  * completeness

Hi Jim,

This is not a restriction of the type-1 query, but of the Bib-1 attribute
set which has been the most generally implemented - simply because it was
included with the standard from the outset. The new general attribute set
architecture is designed exactly to address some of the concerns you
mention - if I understand you correctly, as well as a host of others. The
attribute set architecture is a common framework into which a slew of new
attribute sets are under development. Version 1 of the architecture has
just been released - please check:

<http://lcweb.loc.gov/z3950/agency/attrarch/arch.html>

Please note: I am not arguing whether or not the effort to develop the DASL
protocol is valid, but it is desirable to consider the state of the art in
Z39.50 - if only because the new att. architecture addresses a considerable
amount of practical, dare I say bitter, experience over the past several
years. Perhaps some of those experiences may come in handy.

--Sebastian
--
Sebastian Hammer        <quinn@indexdata.dk>            Index Data ApS
Ph.: +45 3536 3672    <http://www.indexdata.dk>    Fax: +45 3536 0449
                                        ICQ# : 3478927

Received on Saturday, 30 January 1999 12:25:31 UTC