Rails Elasticsearch Aggregation

Rails elasticsearch aggregation

I was also struggling with this, but now I found out how to get the aggregation results.

If you're using the elasticsearch-rails with elasticsearch-model gems, when you run an aggregation on a model, you can get the buckets like in this example:

 agg = Model.search( 
     query: { match: { param: 'value' } }, 
     aggs: {my_aggregation_name: { terms: { field: :my_field} }} 
 )

In your RoR code:

agg.response["aggregations"]["my_aggregation_name"]["buckets"]

From that, you'll get a result like this:

[{"key"=>"banana",
  "doc_count"=>1963,
  "score"=>478.30920868573355,
  "bg_count"=>2152},
 {"key"=>"potato",
  "doc_count"=>1212,
  "score"=>315.68857496078505,
  "bg_count"=>1243}, ...]

Then you can do whatever you want! Hope that helps!

Elasticsearch get results count of other indices with same query

Solution: You can aggregate on field _index.

"group_by_index": {
  "terms": {
    "field": "_index",
    "size": "30"
  }
}

Elastic search - aggregation filter for product options

The prerequisite for such aggregation is to have options field as nested.

Sample index mapping:

PUT test
{
  "mappings": {
    "properties": {
      "title": {
        "type": "keyword"
      },
      "options": {
        "type": "nested",
        "properties": {
          "title": {
            "type": "keyword"
          },
          "value": {
            "type": "keyword"
          }
        }
      }
    }
  }
}

Sample docs:

PUT test/_doc/1
{
  "title": "Roncato Eglo",
  "options": [
    {
      "title": "Mount type",
      "value": "E27"
    },
    {
      "title": "Material",
      "value": "wood"
    }
  ]
}

PUT test/_doc/2
{
  "title": "Eglo",
  "options": [
    {
      "title": "Mount type",
      "value": "E27"
    },
    {
      "title": "Material",
      "value": "metal"
    }
  ]
}

Assumption: For a given document a title under option appears only once. For e.g. there can exists only one nested document under option having title as Material.

Query for aggregation:

GET test/_search
{
  "size": 0, 
  "aggs": {
    "OPTION": {
      "nested": {
        "path": "options"
      },
      "aggs": {
        "TITLE": {
          "terms": {
            "field": "options.title",
            "size": 10
          },
          "aggs": {
            "VALUES": {
              "terms": {
                "field": "options.value",
                "size": 10
              }
            }
          }
        }
      }
    }
  }
}

Response:

{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "OPTION" : {
      "doc_count" : 4,
      "TITLE" : {
        "doc_count_error_upper_bound" : 0,
        "sum_other_doc_count" : 0,
        "buckets" : [
          {
            "key" : "Material",
            "doc_count" : 2,
            "VALUES" : {
              "doc_count_error_upper_bound" : 0,
              "sum_other_doc_count" : 0,
              "buckets" : [
                {
                  "key" : "metal",
                  "doc_count" : 1
                },
                {
                  "key" : "wood",
                  "doc_count" : 1
                }
              ]
            }
          },
          {
            "key" : "Mount type",
            "doc_count" : 2,
            "VALUES" : {
              "doc_count_error_upper_bound" : 0,
              "sum_other_doc_count" : 0,
              "buckets" : [
                {
                  "key" : "E27",
                  "doc_count" : 2
                }
              ]
            }
          }
        ]
      }
    }
  }
}

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