Min Aggregationedit
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.
The min and max aggregation operate on the double representation of
the data. As a consequence, the result may be approximate when running on longs
whose absolute value is greater than 2^53.
Computing the min price value across all documents:
POST /sales/_search?size=0
{
"aggs" : {
"min_price" : { "min" : { "field" : "price" } }
}
}
Response:
{
...
"aggregations": {
"min_price": {
"value": 10.0
}
}
}
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.
Scriptedit
The min aggregation can also calculate the minimum of a script. The example
below computes the minimum price:
POST /sales/_search
{
"aggs" : {
"min_price" : {
"min" : {
"script" : {
"source" : "doc.price.value"
}
}
}
}
}
This will use the Painless scripting language and no script parameters. To use a stored script use the following syntax:
POST /sales/_search
{
"aggs" : {
"min_price" : {
"min" : {
"script" : {
"id": "my_script",
"params": {
"field": "price"
}
}
}
}
}
}
Value Scriptedit
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, let’s 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:
POST /sales/_search
{
"aggs" : {
"min_price_in_euros" : {
"min" : {
"field" : "price",
"script" : {
"source" : "_value * params.conversion_rate",
"params" : {
"conversion_rate" : 1.2
}
}
}
}
}
}
Missing valueedit
The missing parameter defines how documents that are missing a value should
be treated. By default they will be ignored but it is also possible to treat
them as if they had a value.