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From Apache Wiki <wikidi...@apache.org>
Subject [Solr Wiki] Update of "SolrRelevancyFAQ" by jsalvata
Date Thu, 05 Apr 2012 10:12:03 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Solr Wiki" for change notification.

The "SolrRelevancyFAQ" page has been changed by jsalvata:
http://wiki.apache.org/solr/SolrRelevancyFAQ?action=diff&rev1=23&rev2=24

Comment:
Added note about the VERY limited precision of index-time boosts.

  Index-time boosts can be specified per-field also, so only queries matching on that specific
field will get the extra boost.  An Index-time boost on a value of a multiValued field applies
to all values for that field.
  
  Index-time boosts are assigned with the optional attribute "boost" in the <doc> section
of the XML updating messages. See UpdateXmlMessages for more information.
+ 
+ Be aware that all index-time boosts end up being encoded into a single byte using [[http://lucene.apache.org/core/old_versioned_docs/versions/3_5_0/api/core/org/apache/lucene/search/Similarity.html#encodeNormValue%28float%29|Similarity.encodeNormValue]],
which uses a 3-bit mantissa. So differences in boost values of less than 25% may end up being
rounded out.
  
  === Query Elevation Component ===
  To raise certain documents to the top of the result list based on a certain query, one can
use the QueryElevationComponent.

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