Using span queries

The big difference between standard systems (SQL, but also many NoSQL technologies 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. They allow defining the following queries:

• Exact phrase query

• Exact fragment query (that is, Take off, give up)

• Partial exact phrase with a slop parameter (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)

Getting ready

You need a working ElasticSearch cluster.

How to do it...

For executing span queries, we need to perform the following steps:

1. The main element in span queries is the span_term parameter whose usage is similar to the term of standard query.

   One or more span_term parameters can be aggregated to formulate a span query.

   The span_first query defines a query in which the span_term parameter in the first token or near...