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

Alan Kent ajk at mds.rmit.edu.au
Mon May 20 02:39:56 CEST 2002


Hi all,

Sorry, I have been caught up in other things, so I have not had time
to rethink the harvesting stuff for ZeeRex yet.

But a question has arrisen in my mind. How do I define how to do
relational operators such as 'greater-than'? Do we assume always to
use Bib-1? Or should we have another section that lists operators
with registered, agreed to names and interpretations (starting with
Bib-1 relation operators).

For example, I think the GEO profile defines its own greater-than
attribute. GEO also defines 'overlaps' etc operators for regions.
To build up a GEO query, I would rather do it all in the one attribute
set (ie: USE attributes and RELATION attributes all from the GEO
attribute set to allow a V2 query to be specified).

It also allows a server to expose what operators it does support.

Does this seem reasonable?

Alan

ps: Example usage: CQL when it sees 'Age>3' can look up the 'greater-than'
definition in the ZeeRex record to generate RPN attribute lsit correctly.
-- 
Alan Kent (mailto:ajk at mds.rmit.edu.au, http://www.mds.rmit.edu.au/~ajk/)
Project: TeraText Technical Director, InQuirion Pty Ltd (www.inquirion.com)
Postal: Multimedia Database Systems, RMIT, GPO Box 2476V, Melbourne 3001.
Where: RMIT MDS, Bld 91, Level 3, 110 Victoria St, Carlton 3053, VIC Australia.
Phone: +61 3 9925 4114  Reception: +61 3 9925 4099  Fax: +61 3 9925 4098 




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