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From "Uwe Schindler" <...@thetaphi.de>
Subject RE: Absolute term position in scoring
Date Mon, 26 Jan 2015 11:14:48 GMT
Hi,

it depends on the query structure. In fact, SpanFirstQuery is slow (all span queries are slow
because of position use, this may improve in the future).

You question was about using multiple fields - in fact querying for the same terms on multiple
fields and/or different query types: This is the standard approach to tune the relevance!
But it always has a cost. In most cases you will not see a large difference (unless you use
phrase or span queries). A very good explanation what can be done using this is described
in the Elasticsearch Guide: http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/multi-field-search.html

Uwe

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


> -----Original Message-----
> From: Alexey Morozov [mailto:morozov@gmail.com]
> Sent: Monday, January 26, 2015 11:49 AM
> To: java-user@lucene.apache.org
> Subject: Re: Absolute term position in scoring
> 
> Hello!
> 
> I'd like to ask if this approach: construct a complex query consisting of a
> boosted "specialized" part and an "ordinary" part with no boost, - doesn't
> [necessarily] cause a significant performance degradation compared to a
> "custom query", specialized for a particular need.
> 
> Thanks in advance,
> Alexey Morozov
> 
> 26.01.2015 14:57, Michael McCandless пишет:
> > Well you could have ordinary term queries, and then a SHOULD
> > SpanFirstQuery clause with a boost, to give higher scores to those
> > docs that also had the
> > term(s) close to the start of the document.
> >
> >
> > Mike McCandless
> >
> > http://blog.mikemccandless.com
> >
> > On Sun, Jan 25, 2015 at 5:44 PM, Luis A Lastras <lastrasl@us.ibm.com>
> wrote:
> >
> >> Thanks I didn't know about SpanFirstQuery. I can likely get something
> >> going with that. I was still hoping that we could affect the scoring
> >> formula with the position itself, but maybe this is not feasible.
> >>
> >> Luis
> >>
> >>
> >>
> >>    ------------------------------
> >>
> >>
> >>
> >> *Luis A Lastras, Ph.D. Research Staff Member & Manager, Concept
> Analytics,
> >>    IBM Watson*
> >>    *Member of the iBM Academy of Technology*
> >>
> >> *IBM Master Inventor email: **lastrasl@us.ibm.com*
> >> <email@region.ibm.com>
> >> * | Tel: 914-945-3613 <914-945-3613> | Cell: 914-382-1879 <914-382-1879>
> >>    address:  1101 Kitchawan Rd, Office 28-132, Yorktown Heights, NY,
> >> 10598*
> >>
> >>
> >>
> >>
> >>    <http://www.facebook.com/ibmwatson>
> >>
> >>
> >>    ------------------------------
> >>
> >>
> >>
> >> [image: Inactive hide details for Michael McCandless ---01/25/2015
> >> 08:12:18 AM---Maybe SpanFirstQuery? Mike McCandless]Michael
> >> McCandless
> >> ---01/25/2015 08:12:18 AM---Maybe SpanFirstQuery? Mike McCandless
> >>
> >> From: Michael McCandless <lucene@mikemccandless.com>
> >> To: Lucene Users <java-user@lucene.apache.org>
> >> Date: 01/25/2015 08:12 AM
> >> Subject: Re: Absolute term position in scoring
> >> ------------------------------
> >>
> >>
> >>
> >> Maybe SpanFirstQuery?
> >>
> >>
> >> Mike McCandless
> >>
> >> http://blog.mikemccandless.com
> >>
> >> On Sat, Jan 24, 2015 at 9:34 PM, Luis A Lastras <lastrasl@us.ibm.com>
> >> wrote:
> >>
> >>> Is it possible to incorporate in Lucene's scoring function the
> >>> position
> >> of
> >>> a matching term (say as measured from the top of the document). The
> >>> scenario is, if the set of documents tend to lk about the most
> >>> important stuff at the beginning of the document, then we would like
> >>> to give preference to documents that mention a term close to the top.
> >>>
> >>> Thanks,
> >>>
> >>> Luis
> >>>
> >>>
> >>>
> >>>    ------------------------------
> >>>
> >>>
> >>>
> >>> *Luis A Lastras, Ph.D. Research Staff Member & Manager, Concept
> >> Analytics,
> >>>    IBM Watson*
> >>>    *Member of the iBM Academy of Technology*
> >>>
> >>> *IBM Master Inventor email: **lastrasl@us.ibm.com*
> >>> <email@region.ibm.com
> >>>
> >>> * | Tel: 914-945-3613 <914-945-3613> | Cell: 914-382-1879 <914-382-
> 1879>
> >>>    address:  1101 Kitchawan Rd, Office 28-132, Yorktown Heights, NY,
> >> 10598*
> >>>
> >>>
> >>>
> >>>    <http://www.facebook.com/ibmwatson>
> >>>
> >>>
> >>>    ------------------------------
> >>>
> >>>
> >>>
> >>
> 
> 
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