=== Exact-Value Fields

The final topic that we should touch on before leaving multifield queries is that of exact-value not_analyzed fields. ((("not_analyzed fields", "exact value, in multi-field queries")))((("multifield search", "exact value fields")))((("exact values", "exact value not_analyzed fields in multifield search")))((("analyzed fields", "avoiding mixing with not analyzed fields in multi_match queries"))) It is not useful to mix not_analyzed fields with analyzed fields in multi_match queries.

The reason for this can be demonstrated easily by looking at a query explanation. Imagine that we have set the title field to be not_analyzed:


GET /_validate/query?explain { "query": { "multi_match": { "query": "peter smith", "type": "cross_fields", "fields": [ "title", "first_name", "last_name" ] } }


// SENSE: 110_Multi_Field_Search/55_Not_analyzed.json

Because the title field is not analyzed, it searches that field for a single term consisting of the whole query string!

title:peter smith
    blended("peter", fields: [first_name, last_name])
    blended("smith", fields: [first_name, last_name])

That term clearly does not exist in the inverted index of the title field, and can never be found. Avoid using not_analyzed fields in multi_match queries.