What does Elasticsearch's auto_generate_phrase_queries do?

Question

In the docs for query string query, auto_generate_phrase_queries is listed as a parameter but the only description is "defaults to false." So what does this parameter do exactly?

http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html

Answer 1

This will directly match to the lucene's org.apache.lucene.queryparser.classic.QueryParserSettings#autoGeneratePhraseQueries. When the analyzer applied on the query string, this setting allows lucene to generate quoted phrases no keywords.

Quoting:

SOLR-2015: Add a boolean attribute autoGeneratePhraseQueries to TextField. autoGeneratePhraseQueries="true" (the default) causes the query parser to generate phrase queries if multiple tokens are generated from a single non-quoted analysis string. For example WordDelimiterFilter splitting text:pdp-11 will cause the parser to generate text:"pdp 11" rather than (text:PDP OR text:11). Note that autoGeneratePhraseQueries="true" tends to not work well for non whitespace delimited languages.

where word delimiter works as WordDelimiterFilter.html

Important thing to note is single non-quoted analysis string, i.e. if your query string is non-quoted. If you are already searching for a quoted phrase then it won't make any sense.