elasticsearch/docs/reference/query-languages/query-dsl-script-query.md

navigation_title	mapped_pages
Script	https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-script-query.html

Script query [query-dsl-script-query]

::::{note} Runtime fields provide a very similar feature that is more flexible. You write a script to create field values and they are available everywhere, such as fields, all queries, and aggregations. ::::

Filters documents based on a provided script. The script query is typically used in a filter context.

::::{warning} Using scripts can result in slower search speeds. See Scripts, caching, and search speed. ::::

Example request [script-query-ex-request]

GET /_search
{
  "query": {
    "bool": {
      "filter": {
        "script": {
          "script": """
            double amount = doc['amount'].value;
            if (doc['type'].value == 'expense') {
              amount *= -1;
            }
            return amount < 10;
          """
        }
      }
    }
  }
}

You can achieve the same results in a search query by using runtime fields. Use the fields parameter on the _search API to fetch values as part of the same query:

GET /_search
{
  "runtime_mappings": {
    "amount.signed": {
      "type": "double",
      "script": """
        double amount = doc['amount'].value;
        if (doc['type'].value == 'expense') {
          amount *= -1;
        }
        emit(amount);
      """
    }
  },
  "query": {
    "bool": {
      "filter": {
        "range": {
          "amount.signed": { "lt": 10 }
        }
      }
    }
  },
  "fields": [{"field": "amount.signed"}]
}

Top-level parameters for script [script-top-level-params]

script

(Required, script object) Contains a script to run as a query. This script must return a boolean value, true or false.

Notes [script-query-notes]

Custom parameters [script-query-custom-params]

Like filters, scripts are cached for faster execution. If you frequently change the arguments of a script, we recommend you store them in the script’s params parameter. For example:

GET /_search
{
  "query": {
    "bool": {
      "filter": {
        "script": {
          "script": {
            "source": "doc['num1'].value > params.param1",
            "lang": "painless",
            "params": {
              "param1": 5
            }
          }
        }
      }
    }
  }
}

Allow expensive queries [_allow_expensive_queries_4]

Script queries will not be executed if search.allow_expensive_queries is set to false.