Aggregating over _field_names in elasticsearch 5

Question

I\'m trying to aggregate over field names in ES 5 as described in Elasticsearch aggregation on distinct keys But the solution described there is not working anymore.

My

Answer 1

This is probably because setting size: 0 is not allowed anymore in ES 5. You have to set a specific size now.

POST _search
{
    "aggs": {
        "params": {
            "terms": {
                "field": "_field_names",
                "include" : "param.*",   
                "size": 100                <--- change this
            }

        }
    }
}