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From Apache Wiki <wikidi...@apache.org>
Subject [Solr Wiki] Update of "DisMax" by JanHoydahl
Date Tue, 01 Mar 2016 22:52:10 GMT
Dear Wiki user,

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

The "DisMax" page has been changed by JanHoydahl:
https://wiki.apache.org/solr/DisMax?action=diff&rev1=4&rev2=5

Comment:
Point to ref guide

  
  Out of the box, Solr uses the standard Solr query parser which is pretty stupid, understanding
only syntactically correct boolean queries like "title:foo OR body:foo", it can only search
one field by default, and it may very well throw an exception in your face if you put in some
characters it does not like.
  
- Therefore a new, more robust query mode was needed and the [[DisMaxQParserPlugin|DisMax]]
and [[ExtendedDisMax]] Query Parsers were born. They are designed to process simple user entered
phrases (without heavy syntax) and search for the individual words across several fields using
different weighting (boosts) based on the significance of each field, and it should never
throw an exception.
+ Therefore a new, more robust query mode was needed and the !DisMax and !ExtendedDisMax Query
Parsers were born. They are designed to process simple user entered phrases (without heavy
syntax) and search for the individual words across several fields using different weighting
(boosts) based on the significance of each field, and it should never throw an exception.
  
  '''Disjunction''' refers to the fact that your search is executed across multiple fields,
e.g. title, body and keywords, with different relevance weights
  
  '''Max''' means that if your word "foo" matches both title and body, the max score of these
two (probably title match) is added to the score, not the sum of the two as a simple OR query
would do. This gives more control over your ranking.
  
- !DisMax is usually the short name for the actual query parser, so don't be confused. The
old [[DisMaxQParserPlugin|DisMax parser]] has been around for some time, while the new and
more advanced [[ExtendedDisMax|ExtendedDisMax parser]] was introduced in <!> [[Solr3.1]]
as experimental.
+ !DisMax and eDisMax are usually the short name for the actual query parser, so don't be
confused.
  
- There is a Lucid Imagination Blog post that explains the [[http://www.lucidimagination.com/blog/2010/05/23/whats-a-dismax/|origins
and conceptual behavior]] of dismax functionality.
+ Please see the official documentation in the Solr Reference Guide:
+  * https://cwiki.apache.org/confluence/display/solr/The+DisMax+Query+Parser
+  * https://cwiki.apache.org/confluence/display/solr/The+Extended+DisMax+Query+Parser
  

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