Minimum should match context

Use a Painless script to specify the minimum number of terms that a specified field needs to match with for a document to be part of the query results.

Variables

params (Map, read-only)
User-defined parameters passed in as part of the query.
params['num_terms'] (int, read-only)
The number of terms specified to match with.
doc (Map, read-only)
Contains the fields of the current document where each field is a List of values.

Return

int
The minimum number of terms required to match the current document.

API

The standard Painless API is available.

Example

To run this example, first follow the steps in context examples.

Imagine that you want to find seats to performances by your favorite actors. You have a list of favorite actors in mind, and you want to find performances where the cast includes at least a certain number of them. terms_set query with minimum_should_match_script is a way to accomplish this. To make the query request more configurable, you can define min_actors_to_see as a script parameter.

To ensure that the parameter min_actors_to_see doesn’t exceed the number of favorite actors, you can use num_term`s to get the number of actors in the list and `Math.min to get the lesser of the two.

Math.min(params['num_terms'], params['min_actors_to_see'])

The following request finds seats to performances with at least two of the three specified actors.

GET seats/_search
{
    "query" : {
        "terms_set": {
            "actors" : {
                "terms" : ["smith", "earns", "black"],
                "minimum_should_match_script": {
                    "source": "Math.min(params['num_terms'], params['min_actors_to_see'])",
                    "params" : {
                        "min_actors_to_see" : 2
                    }
                }
            }
        }
    }
}