基数聚合计算不同值的近似计数。但是，为什么即使对于存储在单个分片中的索引，它显示的值也不正确？
GET /jobs/_settings
{
"jobs": {
"settings": {
"index": {
"number_of_shards": "1",
...
position_id is long
GET /jobs/_search
{
"size": 0,
"aggs": {
"count_position_id": {
"value_count": {
"field": "position_id"
}
},
"unique_position_id": {
"cardinality": {
"field": "position_id",
"precision_threshold": 40000
}
}
}
}
{
"took": 44,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"failed": 0
},
"hits": {
"total": 52836,
"max_score": 0,
"hits": []
},
"aggregations": {
"unique_position_id": {
"value": 52930
},
"count_position_id": {
"value": 52836
}
}
}