A filter that matches documents matching boolean combinations of other queries. Similar in concept to Boolean query, except that the clauses are other filters. Can be placed within queries that accept a filter.
http://github.com/elasticsearch/elasticsearch/issues/290
http://github.com/elasticsearch/elasticsearch/issues/279
http://github.com/elasticsearch/elasticsearch/issues/294
The has_child filter accepts a query and the child type to run against, and results in parent documents that have child docs matching the query
alias of RangeFilter