ES|QL SET directive

The SET directive can be used to specify query settings that modify the behavior of an ES|QL query.

Syntax

SET setting_name = setting_value[, ..., settingN = valueN]; <query>
		

Multiple SET directives can be included in a single query, separated by semicolons. If the same setting is defined multiple times, the last definition takes precedence.

Allowed settings

unmapped_fields

Defines how unmapped fields are treated. Possible values are: "FAIL" (default) - fails the query if unmapped fields are present; "NULLIFY" - treats unmapped fields as null values. Type: keyword.

Example

Make the field null if it is unmapped.

SET unmapped_fields="nullify";
FROM employees
| KEEP emp_*, foo
| SORT emp_no
| LIMIT 1