Find out which fields matched in a multi match query

Question

I am using a typical multi match query on three fields: name, city, state. The multi match query is also using a Java function score script. Is there any way to know in the score script what fields matched my multi match query? If not, is there any way to figure this out from the SearchResponse object?

I am currently on Elasticsearch 1.2.1 but I can easily upgrade if it's necessary.

Answer 1

I don't believe you can do this directly with just multi match, but if you add highlighting you should get a response showing which fields matched:

http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/highlighting-intro.html

In the example from this page:

    GET /megacorp/employee/_search
    {
        "query" : {
            "match_phrase" : {
                "about" : "rock climbing"
            }
        },
        "highlight": {
            "fields" : {
                "about" : {}
            }
        }

}

you would change the match_phrase to a multi_match and add the field list:

    GET /megacorp/employee/_search
    {
        "query" : {
            "multi_match" : {
                "query" : "rock climbing",
                "fields": ["about", "otherfield"]
            }
        },
        "highlight": {
            "fields" : {
                "about" : {},
                 "otherfield": {}
            }
        }

}

and that should get you a highlight response which includes the highlight around the matching text and the field that was matched.

Answer 2

There is another exact way to find out which field is matched in the query

Because the highlight is post highlight process, it is not accurate because of the way it did

Just use named query to do it instead of multi-match

such as

  {
    "multi_match" : {
      "query" : "query phrase here",
      "fields" : [ "name", "tag", "categorys" ],
      "operator" : "AND"
  }

translate it into bool query with name

    "should": [
        {
            "match": {
               "name": {
                    "query": "query phrase here",
                    "_name":"name_field"
               }
            }
        },{
            "match": {
               "tag":{
                    "query": "query phrase here",
                    "_name":"tag_field"
               }
            }   
        },{
            "match": {
               "categorys":{
                    "query": "query phrase here",
                    "_name":"cat_field"
               }
            }
        }
     ]

it will return the result like that

     {
        "_index": "indexName",
        "_type": "type",
        "_id": "id",
        "_score": 0.27836448,
        "matched_queries": [
           "tag_field"
        ]
     },
     {
        "_index": "indexName",
        "_type": "type",
        "_id": "id",
        "_score": 0.27836448,
        "matched_queries": [
           "name_field",
           "tag_field"
        ]
     }