The regex query allows you to use regular expressions to match terms in the <i>_all</i> field. A detailed overview of lucene's regex engine is available here: <a target="_blank" href="http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-regexp-query.html#regexp-syntax">Regular expressions in Elasticsearch</a><h5>A note on anchoring</h5>Lucene’s patterns are always anchored. The pattern provided must match the entire string. For string "abcde":<p><code>ab.*</code> will match<br><code>abcd</code> will not match</p>