00_Intro.asciidoc

Getting started with languages

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

Arabic, Armenian, Basque, Brazilian, Bulgarian, Catalan, Chinese, Czech, Danish, Dutch, English, Finnish, French, Galician, German, Greek, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Norwegian, Persian, Portuguese, Romanian, Russian, Spanish, Swedish, Turkish, and Thai.

These analyzers typically perform four roles:

• Tokenize text into individual words:

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

• Lowercase tokens:

  The → the

• Remove commom 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 diactrics like ¨ or ^:

  l’église → eglis

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

  äußerst → ausserst