Bucket Selector Aggregation
editBucket Selector Aggregation
editA parent pipeline aggregation which executes a script which determines whether the current bucket will be retained
in the parent multi-bucket aggregation. The specified metric must be numeric and the script must return a boolean value.
If the script language is expression then a numeric return value is permitted. In this case 0.0 will be evaluated as false
and all other values will evaluate to true.
The bucket_selector aggregation, like all pipeline aggregations, executes after all other sibling aggregations. This means that using the bucket_selector aggregation to filter the returned buckets in the response does not save on execution time running the aggregations.
Syntax
editA bucket_selector aggregation looks like this in isolation:
{
"bucket_selector": {
"buckets_path": {
"my_var1": "the_sum",
"my_var2": "the_value_count"
},
"script": "params.my_var1 > params.my_var2"
}
}
|
Here, |
Table 12. bucket_selector Parameters
| Parameter Name | Description | Required | Default Value |
|---|---|---|---|
|
The script to run for this aggregation. The script can be inline, file or indexed. (see Scripting for more details) |
Required |
|
|
A map of script variables and their associated path to the buckets we wish to use for the variable
(see |
Required |
|
|
The policy to apply when gaps are found in the data (see Dealing with gaps in the data for more details) |
Optional |
|
The following snippet only retains buckets where the total sales for the month is more than 200:
POST /sales/_search
{
"size": 0,
"aggs" : {
"sales_per_month" : {
"date_histogram" : {
"field" : "date",
"interval" : "month"
},
"aggs": {
"total_sales": {
"sum": {
"field": "price"
}
},
"sales_bucket_filter": {
"bucket_selector": {
"buckets_path": {
"totalSales": "total_sales"
},
"script": "params.totalSales > 200"
}
}
}
}
}
}
And the following may be the response:
{
"took": 11,
"timed_out": false,
"_shards": ...,
"hits": ...,
"aggregations": {
"sales_per_month": {
"buckets": [
{
"key_as_string": "2015/01/01 00:00:00",
"key": 1420070400000,
"doc_count": 3,
"total_sales": {
"value": 550.0
}
},
{
"key_as_string": "2015/03/01 00:00:00",
"key": 1425168000000,
"doc_count": 2,
"total_sales": {
"value": 375.0
},
}
]
}
}
}