What does setting the not_analyzed index do when converting the index when using elasticsearch?

Question

What does :index => :not_analyzed if I map it to a field or if I don't add it to the field? I could not find the definition on the github bus home page or on elasticsearch.org website.

Code example:

 class Article < ActiveRecord::Base include Tire::Model::Search include Tire::Model::Callbacks #... mapping do indexes :id, :index => :not_analyzed indexes :title, :analyzer => 'snowball', :boost => 100 end end 

Answer 1

Not analyzed means that the field is stored as is, and it is not processed by analysis tools. If you analyze this, you can choose your own analyzer. By default, a standard analyzer is used. This breaks your content in tokens, scribbles them in lower case, removes punctuation, removes English stop words (as, is, are, ...)

I recommend using the analysis API to understand the difference between the analyzers: http://www.elasticsearch.org/guide/reference/api/admin-indices-analyze.html

See the Analysis section for more details: http://www.elasticsearch.org/guide/reference/index-modules/analysis/