Min Aggregation

A single-value metrics aggregation that keeps track and returns the minimum value among numeric values extracted from the aggregated documents. These values can be extracted either from specific numeric fields in the documents, or be generated by a provided script.

Computing the min price value across all documents:

{
    "aggs" : {
        "min_price" : { "min" : { "field" : "price" } }
    }
}

Response:

{
    ...

    "aggregations": {
        "min_price": {
            "value": 10
        }
    }
}

As can be seen, the name of the aggregation (min_price above) also serves as the key by which the aggregation result can be retrieved from the returned response.

Script

Computing the min price value across all document, this time using a script:

{
    "aggs" : {
        "min_price" : { "min" : { "script" : "doc['price'].value" } }
    }
}

The script parameter expects an inline script. Use script_id for indexed scripts and script_file for scripts in the config/scripts/ directory.

Value Script

Let’s say that the prices of the documents in our index are in USD, but we would like to compute the min in EURO (and for the sake of this example, lets say the conversion rate is 1.2). We can use a value script to apply the conversion rate to every value before it is aggregated:

{
    "aggs" : {
        "min_price_in_euros" : {
            "min" : {
                "field" : "price",
                "script" : "_value * conversion_rate",
                "params" : {
                    "conversion_rate" : 1.2
                }
            }
        }
    }
}