Best way to return different years in a ElasticSearch base

Elastic Stack Elasticsearch
1

I posted this question to find out if there is a better way to return
years in a elasticsearch database, Without using aggregations.
the kind of field is this:

{"type" : "date", "format": "dd-MM-yyyy HH:mm:ss"}

Note: I already can return the values using aggregations and date_histogram. This way:

 GET _search
 { "size": 0,
    "aggs": {
        "group_by_doenca": {
            "date_histogram": {
                "field": "data",
                "interval" : "year",
                "format": "yyyy"

            }
        }
    }
}

And is returning me correctly this:

"hits": {
"total": 100000000,
"max_score": 0,
"hits": []
},
"aggregations": {
 "group_by_date": {
 "buckets": [
    {
       "key_as_string": "1995",
       "key": 788918400000,
       "doc_count": 4547094
    },
    {
       "key_as_string": "1996",
       "key": 820454400000,
       "doc_count": 4543451
    },
    {
       "key_as_string": "1997",
       "key": 852076800000,
       "doc_count": 4547131
    }, 
  ....

As you can see, this base has 100kk of "lines" and the return time of this search of is about 5 seconds.

I need only the different years, do not need the doc_count of these years.

So I wonder if there is how to modify this research, to be faster, and only return me the information I need?

Thank you so much

2

Faster? I'm unsure. But may be it will reduce a bit the bandwidth if you use response filtering?

See https://www.elastic.co/guide/en/elasticsearch/reference/2.3/common-options.html#_response_filtering