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elasticsearchaggregation

Elasticsearch The float field becomes integer after aggregations

I have a field, it look like "usage": 66.667. I tried to get sum of this field:

  "aggs": {
    "sum_usage": {
      "sum": {
        "field": "usage"
      }
    }
  }

But after this aggregation I have

 "aggregations" : {
    "sum_usage" : {
      "value" : 66.0
    }
  }

Could you please tell me how does it happens? Why float filed becomes integer?

Solution

  • The reason is because in your index mapping the field is mapped as an integer. You can see this when running the following command:

    GET your-index/_mapping/field/usage

    The reason is that you didn't create your mapping explicitly and you let ES dynamically generate the mapping, which happens when you index your first document. When you did, the very first document must have had an integer value for the usage field (e.g. "1", "0", etc), and hence, the mapping was created with integer instead of float.

    You need to explicitly create the mapping of your index with the proper types for all your fields. Then reindex your data and your query will work as you expect.