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From "Uwe Schindler" <...@thetaphi.de>
Subject RE: Distributed search capability
Date Fri, 10 Jun 2011 18:00:30 GMT
Hi Jason,

Standard MTQ queries have no scoring at all (using ConstantScoreRewrite by
default). Exception is FuzzyQuery which has two modes: One using standard
BQ TermQuery scoring multiplied with factor calculated from levensthein
distance and another one with all TermQueries made constant score and only
boosted by levensthein distance.

For all MTQ queries you can change the rewrite mode (so you can even rewrite
a WildCard query using fuzzy scoring, but that makes no sense at all,
because all boost are 1.0). You can also make FuzzyQ constant and respecting
all terms that match somehow if you like, the standard is to use a PQ.

This is the same in Lucene 3.x.

-----
Uwe Schindler
H.-H.-Meier-Allee 63, D-28213 Bremen
http://www.thetaphi.de
eMail: uwe@thetaphi.de


> -----Original Message-----
> From: Jason Rutherglen [mailto:jason.rutherglen@gmail.com]
> Sent: Friday, June 10, 2011 7:52 PM
> To: dev@lucene.apache.org
> Subject: Re: Distributed search capability
> 
> Out of curiosity, how is DF handled with the new automaton [regex]
queries?
> 
> On Fri, Jun 10, 2011 at 10:48 AM, Andrzej Bialecki <ab@getopt.org> wrote:
> > On 6/10/11 6:27 PM, Michael McCandless wrote:
> >>
> >> I'm actually working on something like this, basically a utility
> >> method to merge N TopDocs into 1.  I want to do this for grouping as
> >> well to make it easy to do grouping across shards.
> >
> > Mike,
> >
> > The straightforward merge that is used in Solr suffers from
> > incomparable scores (due to the lack of global IDF). See my slides from
the
> Buzzwords.
> > Since we can handle global IDF in local searchers more easily that in
> > Solr then we can reuse that DfCache trick from MultiSearcher.
> >
> >
> > --
> > Best regards,
> > Andrzej Bialecki     <><
> >  ___. ___ ___ ___ _ _   __________________________________
> > [__ || __|__/|__||\/|  Information Retrieval, Semantic Web ___|||__||
> > \|  ||  |  Embedded Unix, System Integration http://www.sigram.com
> > Contact: info at sigram dot com
> >
> >
> > ---------------------------------------------------------------------
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> >
> >
> 
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