Rank feature field/query on nested field

Elastic Stack Elasticsearch
1

Hey guys,

I am trying to use the rank feature field/query on a nested object field.

The index is like below:
{
"id": {
"type": "integer"
},
"sources": {
"type": "nested",
"properties": {
"source": {
"type": "text"
}
},
"counter": {
"type": "rank_feature"
}
}
}

one of the example document is
{
"id": 1,
"page": "main",
"sources" : [
{
"counter" : 1,
"source" : "main"
},
{
"counter" : 10,
"source" : "browse"
}
}

Can someone please give some advise how to construct the query which can use the counter as rank feature field to boost?

2

Hello! I am not sure I understand your mapping definition:

            "id": {
                "type": "integer"
            },
            "sources": {
                "type": "nested",
                "properties": {
                    "source": {
                        "type": "text"
                    }
                },
                "counter": {
                    "type": "rank_feature"
                }
            }

Did you intend to put counter under sources properties, like this:

           "id": {
                "type": "integer"
            },
            "sources": {
                "type": "nested",
                "properties": {
                    "source": {
                        "type": "text"
                    },
                    "counter": {
                        "type": "rank_feature"
                    }
                }
            }

There is also seems to be a mistake in the json of the doc for indexing that you provided.

About your question how to construct ranked feature query on a nested field, you do it similarly to any other nested query -- you nest it under nested keyword, like this:

{
    "query": {
		"nested" : {
			"path" : "sources",
			"query" : {
				"rank_feature": {
					"field" : "sources.counter"
				}
			}
		}
    }
}

For the boosting based on the rank_feature query, you put in the should clause, as in the example in the documentation.

{
    "query": {
        "bool": {
            "must": {
                "match": {
                    "page": "main"
                }
            },
            "should": {
                "nested": {
                    "path": "sources",
                    "query": {
                        "rank_feature": {
                            "field": "sources.counter",
                            "boost" : 0.5
                        }
                    },
                    "score_mode": "max"
                }
            }
        }
    }
}