In my ES mapping I have an \'uri\' field which is currently set to not_analysed and I\'m not allowed to change the mapping.I wanted to search for uri parts with a query_string q
From the docs, it seems like you need a new analyzer that first transforms to lowercase and then can run the search. Have you tried that? http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/sorting-collations.html
As I read it, your pattern, lowercase_expanded_terms, only applies to expansions, not to regular words
http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html
lowercase_expanded_terms
Whether terms of wildcard, prefix, fuzzy, and range queries are to be automatically lower-cased or not (since they are not analyzed). Default it true