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From Paul Taylor <paul_t...@fastmail.fm>
Subject Re: NOT_ANALYSED_NO_NORMS should get max field length boost
Date Tue, 12 Jan 2010 17:47:57 GMT

> On Tue, Jan 12, 2010 at 7:53 AM, Paul Taylor <paul_t100@fastmail.fm 
> <mailto:paul_t100@fastmail.fm>> wrote:
>
>     Lucene in Action says you can possibly use NOT_ANALYSED_NO_NORMS
>     when indexing fields that arent tokenized, but later says norms
>     are used to boost fields with less /single term, so matches based
>     on these single term fields would miss out on this boost. Is there
>     a way to use NOT_ANALYSED_NO_NORMS on these fields will will mean
>     they end up with the best boost (1.0 as default) , and then
>     documents that are analysed with norms receive a negative boost
>     (<1.0) if they contain more than one token.
>
>     I'm not using Document or Field boosting, so seems a bit silly for
>     me to store all these norms just to say this field contains a
>     single token and therefore should get an addtional boost.
>
>     Perhaps Im misundersanding this, and this would work as required.
>
>
>     thanks Paul
>
FYI Looking at DefaultSimailarity() the lengthNorm is 1/sqrt(numTerms), 
so for one term would equal 1. i.e. the same as not having norms, so 
AFAIK there is no difference after all if not using Document or field 
boosting

Paul

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