[Ex-plain] Protocol Version (Was: Attribute Searches)
mike at tecc.co.uk
Fri Apr 12 14:54:00 CEST 2002
> Date: Fri, 12 Apr 2002 12:54:09 +0100 (BST)
> From: Robert Sanderson <azaroth at liverpool.ac.uk>
> > > The term of Protocol and the term of ProtocolVersion aren't
> > > really related in terms of categorisation... one's a name the
> > > other is a number (or similar).
> > Sure they are! Search for "z39.50" alone and you want all z39.50
> > (nor SRW) servers; bung in a "version" SQ of "3" and you're asking
> > for version-3 Z39.50 servers. Seems perfect to me.
> How do you know that you want *Z39.50* version three?
Because the access-point is "version" and the term is "z39.50". The
semantic qualifier says, "Oh, and not just _any_ Z39.50 server -- I
only want version 3 servers".
> Can you give an example of how you would actually do the search?
find @attr NET 1=4 @attr NET 2=version3 z39.50
> Or are you saying we should do:
> find @attr NET 1=4 z39.50 AND @attr NET 1=4 2=1 3
> What's the benefit of having it as the same access point with a
> semantic qualifier if you have to always AND it together with the
> same access point for it to make sense?
There would be no benefit to this. The semantic qualifier is a single
attribute which provides additional precision on the access point.
It's not an SQ of type "version" with value "3", but an SQ of value
> This says to me that it's a second access point.
No -- who would ever want to search for version3 alone? That is, for
all servers that support version 3 of a protocol, but we don't care
which protocol? That's meaningless.
/o ) \/ Mike Taylor <mike at miketaylor.org.uk> www.miketaylor.org.uk
)_v__/\ "(12+144+20 + 3*(4^(1/2))) / 7 + 5*11 == 9^2+0" --
unattributed arithmetic limerick, from /usr/games/fortune.
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