Lucene not null query?

Question

How can we construct a query to search for particular field to be not null?

field_name:* is not working. I tried field_name:[a* to z*] this works fine for English, but does not cover all languages.

Any alternative suggestions?

Answer 1

For anyone else arriving late to the question, the documentation includes this little snippet:

• where the field title has any non-null value:
  _exists_:title