The big difference between standard databases (SQL, and also many NoSQL databases, such as MongoDB, Riak, or CouchDB) and Elasticsearch is the number of facilities to express text queries. The span query family is a group of queries that control a sequence of text tokens using their positions: the standard queries don't take care of the positional presence of text tokens.
Span queries allow the defining of several kinds of queries:
- The exact phrase query
- The exact fragment query (that is, take off and give up)
- Partial exact phrase with a slop (other tokens between the searched terms, that is, the man with slop 2 can also match the strong man, the old wise man, and so on).
