An application of range queries is the possibility to perform existence queries, i.e. to match all documents that have a value in a field (a sort of NOT NULL). For example, to find all documents that have a link to the fulltext, you can type:

      +fulltext:[* TO *]

This can be negated to find documents that do not have a value for the field:

      -fulltext:[* TO *]

Now the advanced search allows to build these queries by selecting the type of the query (posive or negative) and the field that we want to query.