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From Beady Geraghty <beadygerag...@gmail.com>
Subject Re: need some advice/help with negative query.
Date Fri, 06 Jan 2006 21:07:18 GMT
Thank you all for your answer.

On 1/6/06, Yonik Seeley <yseeley@gmail.com> wrote:
>
> Should we should detect the case of all negative clauses and throw in
> a MatchAllDocsQuery?
>
> I guess this would be done in the QueryParser, but one could also make
> a case for doing it in the BooleanQuery.
>
> -Yonik
>
> On 1/6/06, Erik Hatcher <erik@ehatchersolutions.com> wrote:
> > With Lucene's trunk, there is a MatchAllDocsQuery.   You could use
> > this in a BooleanQuery with your negative-only query.
> >
> > Another option, if you're at Lucene 1.4.3 is to index the same value
> > for a dummy field for every document (say like "dummy:all") and use a
> > TermQuery in a BooleanQuery with the negative-only query.
> >
> > As for BitSet's, if you need to go that route a QueryFilter would
> > give you the BitSet back that you could easily complement, but that
> > might be a bit overkill for what you need given the option above.
> >
> >         Erik
> >
> >
> > On Jan 6, 2006, at 12:04 PM, Beady Geraghty wrote:
> >
> > > I would like to do queries that are negative. I mean a query with
> > > only negative terms and phrases.  For example, retrieve all
> > > documents that do not contain the term "apple".
> > >
> > > For now, I have a limited set of documents (say, 10000) to index.
> > > I can create a bitset that represents the search result of hits on
> > > "apple".
> > > Then I complement (XOR) the result.
> > > Each bit corresponds to a document ID.
> > > My question is :
> > > Inside Lucene, are the hits represented in some form of a bitset.
> > > Can I get at it directly.   I saw the BitSet class.  (I now use
> > > Java's Bitset class).
> > > Assuming that hits are internally represented as bitset, for a
> > > small number of documets, the bitset won't be very big,
> > > and if there are plenty of hits and many many more documents,
> > > is the bitset still  kept entirely
> > > in memory as well ?
> > >
> > > Thank you
> >
> >
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> >
> >
>
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