Elasticsearch Aggregations Cardinality Aggregation
Example
A single-value metrics aggregation that calculates an approximate count of distinct values. Values can be extracted either from specific fields in the document or generated by a script.
POST /index/_search?size=0
{
"aggs" : {
"type_count" : {
"cardinality" : {
"field" : "type"
}
}
}
}
Response:
{
...
"aggregations" : {
"type_count" : {
"value" : 3
}
}
}
