00_Intro.asciidoc

Getting Started with Languages

Elasticsearch ships with a collection of language analyzers that provide good, basic, out-of-the-box support for many of the world’s most common languages.

These analyzers typically perform four roles:

• Tokenize text into individual words:

  The quick brown foxes → [The, quick, brown, foxes]

• Lowercase tokens:

  The → the

• Remove common stopwords:

  [`The`, quick, brown, foxes] → [quick, brown, foxes]

• Stem tokens to their root form:

  foxes → fox

Each analyzer may also apply other transformations specific to its language in order to make words from that language more searchable:

• The english analyzer removes the possessive 's:

  John’s → john

• The french analyzer removes elisions like l' and qu' and diacritics like ¨ or ^:

  l’église → eglis

• The german analyzer normalizes terms, replacing ä and ae with a, or ß with ss, among others:

  äußerst → ausserst