[Ex-plain] ZeeRex - add 'operators'?

Mike Taylor mike at tecc.co.uk
Wed May 22 12:36:03 CEST 2002

> Date: Wed, 22 May 2002 11:52:42 +1000
> From: Alan Kent <ajk at mds.rmit.edu.au>
> > > Then why bother having [truncation/relation specification] at all?
> Because without it,
> * I cannot express a greater than query
> * I cannot express a truncation query
> I have a database that supports the GEO attribute set, but not Bib-1.
> That is, no Bib-1 attributes are supported at all. How do I do a query
> on it? I know the attribute list for index names that I can search on.
> But I do not know the attribute to add to do right truncation.

Oops.  Alan, you are -- of course -- completely right.

(You can keep GEO, but I'll need to explain how to use the attribute
architecture's utility set to truncate search terms used with the
Zthes profile and other new profiles.  Er -- including ZeeRex!)

> I am trying to avoid mandating Bib-1 knowledge in CCL/CQL -> RPN
> conversions.

Yes, that would be a disaster.

> How about something like:
>     New section listing all operators and the attribute lists they
>     bind to for this database (right-truncate, greater-than,
>     overlaping-region) (as I proposed previously).
>     For each index, list all the operator names supported by that
>     index.  (This is in addition to my previous proposal.)

Still sounds heavyweight to me.  Do we honestly envisage a single
database in which the same truncation is done in different ways on
different indexes?  "To right-truncate searches on the AUTHOR index,
use BIB-1's 5=1, but to on the TITLE index, use the Utility set's 5=4"

I don't.  Let's just give a single list of truncations and relations
at the top level, with the understanding that all indexes which
support any given truncation or relations do so using the specified
attribute.  It's easy enough to discover if a particular index doesn't
support right-truncation at all.

 _/|_	 _______________________________________________________________
/o ) \/  Mike Taylor   <mike at miketaylor.org.uk>   www.miketaylor.org.uk
)_v__/\  "What is this talk of 'release'?  Klingons do not make
	 software 'releases'.  Our software 'escapes,' leaving a
	 bloody trail of designers and quality assurance people in
	 its wake." -- Klingon Programming Mantra

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