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From "Rob Staveley (Tom)" <rstave...@seseit.com>
Subject RE: What are norms?
Date Fri, 14 Jul 2006 14:38:38 GMT
I'm trying to reduce the memory requirement of my application that has ~40
indexed fields. Would I be wasting my time omitting norms in this
application?

What would I lose by omitting norms? The ability to boost individual fields
as they are added to the index? Anything else?

[I want to check that I can get away without knowing about norms :-)]

-----Original Message-----
From: Yonik Seeley [mailto:yseeley@gmail.com] 
Sent: 10 July 2006 18:01
To: java-user@lucene.apache.org
Subject: Re: What are norms?

Norms are per indexed-field.  For every document it's the product of the
lengthNorm and the index-time boost.  It's really more of an implementation
detail that you shouldn't need to know about unless you have a lot of
indexed fields and want to omit them for memory reasons.

See DefaultSimilarity javadoc for lengthNorm... it's what makes hits on
shorter fields score higher.

-Yonik
http://incubator.apache.org/solr Solr, the open-source Lucene search server

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