[Ex-plain] ZeeRex - add 'operators'?
ajk at mds.rmit.edu.au
Mon May 20 02:39:56 CEST 2002
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?
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.
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