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Whitespace Analyzer
The whitespace
analyzer divides text into searchable terms (tokens)
wherever it finds a whitespace character. It leaves all text in its
original letter case.
Important
Atlas Search won't index string fields that exceed 32766 bytes in size.
Example
The following example index definition specifies an index on
the title
field in the sample_mflix.movies
collection using the whitespace
analyzer. If you loaded the
collection on your cluster, you can create the example index using
the Atlas UI Visual Editor or the JSON Editor. After you select
your preferred configuration method, select the database and collection.
The following query searches for the term Lion's
in the title
field.
db.movies.aggregate([ { "$search": { "text": { "query": "Lion's", "path": "title" } } }, { "$project": { "_id": 0, "title": 1 } } ])
[ { title: 'Lion's Den' }, { title: 'The Lion's Mouth Opens' } ]
Atlas Search returns these documents by doing the following for the text in the
title
field using the lucene.whitespace
analyzer:
Retain the original letter case for the text.
Divide the text into tokens wherever it finds a whitespace character.
The following table shows the tokens (searchable terms) that Atlas Search creates using the Whitespace Analyzer and, by contrast, the Simple Analyzer and Keyword Analyzer for the documents in the results:
Title | Whitespace Analyzer Tokens | Simple Analyzer Tokens | Keyword Analyzer Tokens |
---|---|---|---|
Lion's Den | Lion's , Den | lion , s , den | Lion's Den |
The Lion's Mouth Opens | The , Lion's , Mouth , Opens | the , lion , s , mouth , opens | The Lion's Mouth Opens |
The index that uses whitespace
analyzer is case-sensitive.
Therefore, Atlas Search is able to match the query term Lion's
to the token
Lion's
created by the whitespace
analyzer.