Bucket sort in composite aggregation? - elasticsearch

Question

How can I do Bucket Sort in composite Aggregation?
I need to do Composite Aggregation with Bucket sort.
I have tried Sort with aggregation.
I have tried composite aggregation.

Answer 1

I think this question, is in continuation to your previous question, so considered the same use case
You need to use Bucket sort aggregation that is a parent pipeline
aggregation which sorts the buckets of its parent multi-bucket
aggregation. And please refer to this documentation on composite
aggregation to know more about this.
Adding a working example with index data, mapping, search query, and search result
Index Mapping:
{
"mappings":{
"properties":{
"user":{
"type":"keyword"
},
"date":{
"type":"date"
}
}
}
}
Index Data:
{
"date": "2015-01-01",
"user": "user1"
}
{
"date": "2014-01-01",
"user": "user2"
}
{
"date": "2015-01-11",
"user": "user3"
}
Search Query:
The size parameter can be set to define how many composite buckets
should be returned. Each composite bucket is considered as a single
bucket, so setting a size of 10 will return the first 10 composite
buckets created from the values source. The response contains the
values for each composite bucket in an array containing the values
extracted from each value source. Defaults to 10.
{
"size": 0,
"aggs": {
"my_buckets": {
"composite": {
"size": 3, <-- note this
"sources": [
{
"product": {
"terms": {
"field": "user"
}
}
}
]
},
"aggs": {
"mySort": {
"bucket_sort": {
"sort": [
{
"sort_user": {
"order": "desc"
}
}
]
}
},
"sort_user": {
"min": {
"field": "date"
}
}
}
}
}
}
Search Result:
"aggregations": {
"my_buckets": {
"after_key": {
"product": "user3"
},
"buckets": [
{
"key": {
"product": "user3"
},
"doc_count": 1,
"sort_user": {
"value": 1.4209344E12,
"value_as_string": "2015-01-11T00:00:00.000Z"
}
},
{
"key": {
"product": "user1"
},
"doc_count": 1,
"sort_user": {
"value": 1.4200704E12,
"value_as_string": "2015-01-01T00:00:00.000Z"
}
},
{
"key": {
"product": "user2"
},
"doc_count": 1,
"sort_user": {
"value": 1.3885344E12,
"value_as_string": "2014-01-01T00:00:00.000Z"
}
}
]
}