I am on ES 5.2.x and no matter what I try, I cannot get ES to highlight on a matched field when using "_all" as the field indicator for a query. I specify "*" in the highlight clause, but no highlights returned.
What I want is to return highlights on matching fields WITHOUT having to know in advance what fields those are.
Since I can specify "_all" for a field, I would think this would happen automatically. But it doesn't.
Is it possible?