世界上并没有完美的程序,但是我们并不因此而沮丧,因为写程序就是一个不断追求完美的过程。
问:histogram有什么特点?
答:
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsIiclRnblN2XjlGcjYTMfhHLlN3XnxCM38FdsYkRGZkRG9lcvx2bjxCMy8VZ6l2csYWe3cTa2EWNhJTW1UUc1UjQDxkN2lGc1oVLMZTQClGVF5UMR9Fd4VGdsATNfd3bkFGazxycykFaKdkYzZUbapXNXlleSdVY2pESa9VZwlHdssmch1mclRXY39CXldWYtlWPzNXZj9mcw1ycz9WL49zZuBnLmJDZjZzM2YmN3QmYwEWZhBTZjRzN3E2YlNGZhJmZiF2Lc52YucWbp5GZzNmLn9Gbi1yZtl2Lc9CX6MHc0RHaiojIsJye.png)
问:histogram如何使用?
答:
# 删除
DELETE /histogram_test
# 映射
PUT /histogram_test
{
"mappings": {
"properties": {
"num": {"type": "integer"}
}
}
}
# 索引
POST /histogram_test/_bulk?routing=1&refresh
{"index": {"_id": 1}}
{"num": 1}
{"index": {"_id": 2}}
{"num": 3}
{"index": {"_id": 3}}
{"num": 5}
{"index": {"_id": 4}}
{"num": 10}
{"index": {"_id": 5}}
{"num": 80}
# 搜索
GET /histogram_test/_search?size=0
{
"aggs": {
"num_aggs": {
"histogram": {
"field": "num",
"interval": 5,
"keyed": true,
"min_doc_count": 1,
"order": {
"_key": "desc"
},
"offset": 3
}
}
}
}
# 结果
{
"took" : 1,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 5,
"relation" : "eq"
},
"max_score" : null,
"hits" : [ ]
},
"aggregations" : {
"num_aggs" : {
"buckets" : {
"78.0" : {
"key" : 78.0,
"doc_count" : 1
},
"8.0" : {
"key" : 8.0,
"doc_count" : 1
},
"3.0" : {
"key" : 3.0,
"doc_count" : 2
},
"-2.0" : {
"key" : -2.0,
"doc_count" : 1
}
}
}
}
}