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From Doug Cutting <>
Subject RE: Problems with prohibited BooleanQueries
Date Thu, 01 Nov 2001 15:48:46 GMT
> From: Scott Ganyo []
> How difficult would it be to get BooleanQuery to do a 
> standalone NOT, do you
> suppose?  That would be very useful in my case.

It would not be that difficult, but it would make queries slow.  All terms
not containing a term would need to be enumerated.  Since most terms occur
in only a small percentage of the documents, most NOT queries would return
most documents.

Scoring would also be strange.  I guess you'd give them all a score of 1.0,
and hope that the query is nested in a more complex query that will
differentiate the scores.  But if it's nested, then you could do it with
BooleanQuery as it stands...

So, my question to you is: do you actually want lists of all documents that
do not contain a term, or, rather, do you want to use negation in the
context of other query terms, and are having trouble getting your query
parser to build BooleanQueries?


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