es - elasticsearch mapping - meta fields - 5

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 ：_size有什么特点？
答 ：

问 ：_size如何使用？
答 ：

# _size 首先安装mapper-size插件
PUT /size_test
{
  "mappings" : {
    "_size" : {
      "enabled" : true
    },
    "properties" : {
      "name" : {"type" : "text"}
    }
  }
}

# 索引
POST /size_test/_doc/1
{
  "name" : "hello good"
}

# 索引
POST /size_test/_doc/2
{
  "name" : "hello this is me"
}

# 搜索
GET /size_test/_search
{
  "query" : {
    "range" : {
      "_size" : {
        "lt" : 50
      }
    }
  },
  "aggs" : {
    "sizes" : {
      "terms" : {
        "field" : "_size",
        "size"  : 10
      }
    }
  },
  "sort" : [
    {
      "_size" : {
        "order" : "desc"
      }
    }
  ],
  "script_fields" : {
    "size" : {
      "script": "doc['_size']"
    }
  },
  "docvalue_fields" : [
    {"field" : "_size"}
  ]
}

# 结果
{
  "took" : 2,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [
      {
        "_index" : "size_test",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : null,
        "fields" : {
          "_size" : [
            34
          ],
          "size" : [
            34
          ]
        },
        "sort" : [
          34
        ]
      },
      {
        "_index" : "size_test",
        "_type" : "_doc",
        "_id" : "1",
        "_score" : null,
        "fields" : {
          "_size" : [
            28
          ],
          "size" : [
            28
          ]
        },
        "sort" : [
          28
        ]
      }
    ]
  },
  "aggregations" : {
    "sizes" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : 28,
          "doc_count" : 1
        },
        {
          "key" : 34,
          "doc_count" : 1
        }
      ]
    }
  }
}