es - elasticsearch - aggs - bucket - geohash

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：geohash_grid有什么特点？
答：

问：geohash_grid如何使用？
答：

# 删除
DELETE /geohash_grid_test

# 映射
PUT /geohash_grid_test
{
  "mappings": {
    "properties": {
      "loc": {"type": "geo_point"}
    }
  }
}

# 索引
POST /geohash_grid_test/_bulk?routing=1&refresh
{"index": {"_id": 1}}
{"loc": "13, 15"}
{"index": {"_id": 2}}
{"loc": "14, 16"}
{"index": {"_id": 3}}
{"loc": "16, 18"}
{"index": {"_id": 4}}
{"loc": "17, 19"}
{"index": {"_id": 5}}
{"loc": "18, 20"}


# 搜索
GET /geohash_grid_test/_search?size=0
{
  "aggs": {
    "geohash_grid_aggs": {
      "geohash_grid": {
        "field": "loc",
        "precision": 3,
        "bounds": {
          "top_left": "20,10",
          "bottom_right": "14,1"
        }
      }
    }
  }
}

# 搜索 - 根据上一个的key选择区域放大，让精度变大
GET /geohash_grid_test/_search?size=0
{
  "aggs": {
    "geohash_grid_aggs": {
      "geohash_grid": {
        "field": "loc",
        "precision": 8,
        "bounds": {
          "top_left": "s7j",
          "bottom_right": "s7j"
        }
      }
    }
  }
}

# 搜索
GET /geohash_grid_test/_search?size=0
{
  "aggs": {
    "geohash_grid_aggs": {
      "filter": {
        "geo_bounding_box": {
          "loc": {
            "top_left": {
              "lat": 20,
              "lon": 10
            },
            "bottom_right": {
              "lat": 14,
              "lon": 1
            }
          }
        }
      },
      "aggs": {
        "inner_grid": {
          "geohash_grid": {
            "field": "loc",
            "precision": 9
          }
        }
      }
    }
  }
}