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

Robert Sanderson azaroth at liverpool.ac.uk
Wed May 22 13:51:51 CEST 2002


> >     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"

No, and you couldn't describe this in Alan's suggestion anyway.

But there will be Lots of indexes that don't support all the different 
attributes.

> 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.

By testing and seeing if it fails you, the same way as you can test a USE 
attribute and see if it fails...

I agree with Alan here, something like the following isn't too much work.  
And if people don't want to put it in, then they don't have to.

<operators>
<operator key="&lt;">
  <title>greater than</title>
  <map>
      <attr type="2">102</attr>
  </map>
</operator>
</operators>

<index>
...
<operators>
  <operator key="&lt;"/>
  <operator key="&gt;"/>
  <operator key="@PROX@"/>
</operators>
</index>

(numbers and names are off the top of my head)

Rob


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