109 lines
3.0 KiB
Plaintext
109 lines
3.0 KiB
Plaintext
[[search-aggregations-pipeline-max-bucket-aggregation]]
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=== Max Bucket Aggregation
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coming[2.0.0]
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experimental[]
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A sibling pipeline aggregation which identifies the bucket(s) with the maximum value of a specified metric in a sibling aggregation
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and outputs both the value and the key(s) of the bucket(s). The specified metric must be numeric and the sibling aggregation must
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be a multi-bucket aggregation.
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==== Syntax
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A `max_bucket` aggregation looks like this in isolation:
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[source,js]
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--------------------------------------------------
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{
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"max_bucket": {
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"buckets_path": "the_sum"
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}
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}
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--------------------------------------------------
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.`max_bucket` Parameters
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|===
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|Parameter Name |Description |Required |Default Value
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|`buckets_path` |The path to the buckets we wish to find the maximum for (see <<bucket-path-syntax>> for more
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details) |Required |
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|`gap_policy` |The policy to apply when gaps are found in the data (see <<gap-policy>> for more
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details)|Optional, defaults to `skip` |
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|`format` |format to apply to the output value of this aggregation |Optional, defaults to `null` |
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|===
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The following snippet calculates the maximum of the total monthly `sales`:
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[source,js]
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--------------------------------------------------
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{
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"aggs" : {
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"sales_per_month" : {
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"date_histogram" : {
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"field" : "date",
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"interval" : "month"
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},
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"aggs": {
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"sales": {
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"sum": {
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"field": "price"
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}
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}
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}
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},
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"max_monthly_sales": {
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"max_bucket": {
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"buckets_paths": "sales_per_month>sales" <1>
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}
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}
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}
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}
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--------------------------------------------------
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<1> `bucket_paths` instructs this max_bucket aggregation that we want the maximum value of the `sales` aggregation in the
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`sales_per_month` date histogram.
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And the following may be the response:
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[source,js]
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--------------------------------------------------
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{
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"aggregations": {
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"sales_per_month": {
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"buckets": [
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{
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"key_as_string": "2015/01/01 00:00:00",
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"key": 1420070400000,
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"doc_count": 3,
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"sales": {
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"value": 550
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}
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},
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{
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"key_as_string": "2015/02/01 00:00:00",
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"key": 1422748800000,
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"doc_count": 2,
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"sales": {
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"value": 60
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}
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},
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{
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"key_as_string": "2015/03/01 00:00:00",
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"key": 1425168000000,
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"doc_count": 2,
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"sales": {
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"value": 375
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}
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}
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]
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},
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"max_monthly_sales": {
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"keys": ["2015/01/01 00:00:00"], <1>
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"value": 550
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}
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}
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}
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--------------------------------------------------
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<1> `keys` is an array of strings since the maximum value may be present in multiple buckets
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