While the documentation of inner hits shows that sort can be used to overwrite the default sorting (by _score) of my inner hits I can't seem to access `_score' itself.
The documentation of Sort suggests that I can access _sort and _doc. And while _doc is indeed accessible, I didn't manage to access _score. What did I do wrong?
POST /books_v2/_search
{
"size": 1,
"_source": [
"bookratings"
],
"query": {
"function_score": {
"query": {
"nested": {
"path": "editions",
"score_mode": "max",
"query": {
"bool": {
"must": [
{
"match": {
"editions.title_author_unique": {
"query": "harry",
"operator": "and",
"fuzziness": "AUTO"
}
}
}
]
}
},
"inner_hits": {
"size": 1,
"_source": false,
"sort": {
"_script": {
"type": "number",
"script": {
"lang": "painless",
"source": """return _score;"""
},
"order": "desc"
}
}
}
}
},
"script_score": {
"script": """return _score;"""
}
}
}
}
results in
{
"took": 40,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 37,
"max_score": 15.269544,
"hits": [
{
"_index": "books_v2",
"_type": "_doc",
"_id": "1845",
"_score": 15.269544, //_score is used for sorting
"_source": {
"bookratings": 37
},
"inner_hits": {
"editions": {
"hits": {
"total": 1,
"max_score": null,
"hits": [
{
"_index": "books_v2",
"_type": "_doc",
"_id": "1845",
"_nested": {
"field": "editions",
"offset": 16
},
"_score": null, // original score is not used, instead _score is null
"sort": [
0
]
}
]
}
}
}
}
]
}
}