How to get the parent document in a nested top_hits aggregation? - elasticsearch

Question

This is my document/mapping with a nested prices array:
{
"name": "Foobar",
"type": 1,
"prices": [
{
"date": "2016-03-22",
"price": 100.41
},
{
"date": "2016-03-23",
"price": 200.41
}
]
}
Mapping:
{
"properties": {
"name": {
"index": "not_analyzed",
"type": "string"
},
"type": {
"type": "byte"
},
"prices": {
"type": "nested",
"properties": {
"date": {
"format": "dateOptionalTime",
"type": "date"
},
"price": {
"type": "double"
}
}
}
}
}
I use a top_hits aggregation to get the min price of the nested price array. I also have to filter the prices by date. Here is the query and the response:
POST /index/type/_search
{
"size": 0,
"query": {
"match_all": {}
},
"aggs": {
"prices": {
"nested": {
"path": "prices"
},
"aggs": {
"date_filter": {
"filter": {
"range": {
"prices.date": {
"gte": "2016-03-21"
}
}
},
"aggs": {
"min": {
"top_hits": {
"sort": {
"prices.price": {
"order": "asc"
}
},
"size": 1
}
}
}
}
}
}
}
}
Response:
{
"took": 3,
"timed_out": false,
"_shards": {
"total": 3,
"successful": 3,
"failed": 0
},
"hits": {
"total": 2,
"max_score": 0,
"hits": [
]
},
"aggregations": {
"prices": {
"doc_count": 4,
"date_filter": {
"doc_count": 4,
"min": {
"hits": {
"total": 4,
"max_score": null,
"hits": [
{
"_index": "index",
"_type": "type",
"_id": "4225796ALL2016061541031",
"_nested": {
"field": "prices",
"offset": 0
},
"_score": null,
"_source": {
"date": "2016-03-22",
"price": 100.41
},
"sort": [
100.41
]
}
]
}
}
}
}
}
}
Is there a way to get the parent source document (or some fields from it) with _id="4225796ALL2016061541031" in the response (e.g. name)? A second query is not an option.

Answer 1

Instead of applying aggregations use query and inner_hits like :
{
"query": {
"nested": {
"path": "prices",
"query": {
"range": {
"prices.date": {
"gte": "2016-03-21"
}
}
},
"inner_hits": {
"sort": {
"prices.price": {
"order": "asc"
}
},
"size": 1
}
}
}
}
Fetch data of parent_documentdata from _source and actual data from inner_hits.
Hope it helps