Numerical fields

[Stadler Hans-Christian <ha...@psi.ch>]

Is there an enhancment/plugin to Lucene which would allow
queries like

myNumericalField > 100

I know that usually one has to index such fields as text with
the property   a > b => lex(text(a)) > lex(text(b))  and devise
the text(n) transformation appropriately.

What I'm looking for is an enhancement which would eliminate
the a -> text(a) transformation or simplify it. Is it necessary f.ex.
to implement the above query as a range query

100 <= myNumericalField <= 999999999999999999999999.....

Since many people use numeric field, I guess there exists some
enhancement allready that simplifz the treatment of numerical fields.

HC

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Re: Numerical fields

[Chris Hostetter <ho...@fucit.org>]

: I know that usually one has to index such fields as text with
: the property   a > b => lex(text(a)) > lex(text(b))  and devise
: the text(n) transformation appropriately.
:
: What I'm looking for is an enhancement which would eliminate
: the a -> text(a) transformation or simplify it. Is it necessary f.ex.

the transformation has to happen either way, so the best we can do is
create it and put it in a utility ... NumberTools already meets this need
for longs, but there are some other utils in Solr that could be promoted
if someone wants to do so.

: to implement the above query as a range query
:
: 100 <= myNumericalField <= 999999999999999999999999.....

that's just not true ... ConstantScoreRangeQuery can support open ended
ranges -- there is no need to specify an artificial uper bound.



-Hoss


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Re: Numerical fields

[Doron Cohen <DO...@il.ibm.com>]

karl wettin wrote:

>
> 11 maj 2007 kl. 18.16 skrev Stadler Hans-Christian:
>
> > Is there an enhancment/plugin to Lucene which would allow
> > queries like
> >
> > myNumericalField > 100
>
> FunctionQuery might be what you are looking for.
>
> http://issues.apache.org/jira/browse/LUCENE-446

LUCENE-446 allows also score manipulation. It can also be
used to filter docs by assigning 0 score to out-of-range
docs.

But note two aspects of using search.function: (1) values
cannot exceed Integer.MAX_VALUE. (some examples given
here had larger values...)   (2) all values are loaded
(once, cached) into memory, so expect RAM usage of
numDocs * 1/2/4/8 bytes, depending on the maximal
needed value.

A user discussion that may be relevant:
http://www.mail-archive.com/java-user@lucene.apache.org/msg11965.html

>
> --
> karl


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Re: Numerical fields

[karl wettin <ka...@gmail.com>]

11 maj 2007 kl. 18.16 skrev Stadler Hans-Christian:

> Is there an enhancment/plugin to Lucene which would allow
> queries like
>
> myNumericalField > 100

FunctionQuery might be what you are looking for.

http://issues.apache.org/jira/browse/LUCENE-446

-- 
karl

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