How to read the JSON output of a faceted search query? - elasticsearch

Question

I am having Movies that belong to a genre and have multiple ratings. With ElasticSearch, I want to do a faceted search on Genres first, and then Ratings.
I was reading about the idea here: http://www.elasticsearch.org/guide/reference/api/search/facets/
But I am confused how to understand the output of this Curl query:
curl -X POST "http://localhost:9200/movies/_search?pretty=true" -d '
{
"query" : { "query_string" : {"query" : "T*"} },
"facets" : {
"categories" : { "terms" : {"field" : "categories"} }
}
}
'
{
"took" : 35,
"timed_out" : false,
"_shards" : {
"total" : 5,
"successful" : 5,
"failed" : 0
},
"hits" : {
"total" : 3,
"max_score" : 1.0,
"hits" : [ {
"_index" : "movies",
"_type" : "movie",
"_id" : "13",
"_score" : 1.0, "_source" : {"category_id":2,"created_at":"2013-05-03T16:40:21Z","description":null,"title":"Tiny Plastic Men","updated_at":"2013-05-03T16:40:21Z","user_id":null}
}, {
"_index" : "movies",
"_type" : "movie",
"_id" : "32",
"_score" : 1.0, "_source" : {"category_id":14,"created_at":"2013-05-03T16:55:02Z","description":null,"title":"The Extreme Truth","updated_at":"2013-05-03T16:55:02Z","user_id":null}
}, {
"_index" : "movies",
"_type" : "movie",
"_id" : "39",
"_score" : 1.0, "_source" : {"category_id":7,"created_at":"2013-05-03T16:55:02Z","description":null,"title":"A Time of Day","updated_at":"2013-05-03T16:55:02Z","user_id":null}
} ]
},
"facets" : {
"categories" : {
"_type" : "terms",
"missing" : 3,
"total" : 0,
"other" : 0,
"terms" : [ ]
}
}
I am having some movies that start with a 'T', but additionally I would expect movies from the Genre/Category 'Thriller'.
Therefore, what can I read from the JSON above?

Answer 1

It seems like your facet does not match any fields in your document you should probably use:
curl -X POST "http://localhost:9200/movies/_search?pretty=true" -d '
{
"query" : { "query_string" : {"query" : "T*"} },
"facets" : {
"categories" : { "terms" : {"field" : "category_id"} }
}
}
'
then you sould get a list of category_id and a count of documents in each category_id

Answer 2

Facets are deprecated. See https://www.elastic.co/guide/en/elasticsearch/reference/1.6/search-facets.html
Better alternative is to use aggregations: https://www.elastic.co/guide/en/elasticsearch/reference/1.6/search-aggregations.html