此次操作的结果是，在使用ik_smart作为analyzer和search_analyzer的情况下

（1）prefix completion 效果较为理想

（2）term / phrase suggest 均没有得到想要的效果

为什么用ik_smart? 不是ik_max_word?

ik_max_word是最大颗粒度的进行分词，对我们检索的关键字会进行最大颗粒度的分词，鉴于es进行suggest的机制，在进行最大颗粒度分词后，suggest效果应该不会理想

实际上，在设置ik_max_word分词后确实也没有得到想要的效果

POST /ocr2/_analyze
{
  "analyzer": "ik_smart",
  "text": ["好记性使用手册不如烂笔头感叹号博客园"]
}

# result
{
  "tokens" : [
    {
      "token" : "好记性",
      "start_offset" : 0,
      "end_offset" : 3,
      "type" : "CN_WORD",
      "position" : 0
    },
    {
      "token" : "使用手册",
      "start_offset" : 3,
      "end_offset" : 7,
      "type" : "CN_WORD",
      "position" : 1
    },
    {
      "token" : "不如",
      "start_offset" : 7,
      "end_offset" : 9,
      "type" : "CN_WORD",
      "position" : 2
    },
    {
      "token" : "烂",
      "start_offset" : 9,
      "end_offset" : 10,
      "type" : "CN_CHAR",
      "position" : 3
    },
    {
      "token" : "笔头",
      "start_offset" : 10,
      "end_offset" : 12,
      "type" : "CN_WORD",
      "position" : 4
    },
    {
      "token" : "博客园",
      "start_offset" : 15,
      "end_offset" : 18,
      "type" : "CN_WORD",
      "position" : 5
    }
  ]
}

PUT /ocr2
{
  "mappings" : {
    "properties" : {
    "text": { 
            "type": "text",
            "analyzer":"ik_smart",
            "search_analyzer":"ik_smart"
        },
        "pageid": { 
            "type": "completion",
            "search_analyzer": "ik_max_word",
            "analyzer": "ik_max_word"
        }
    }
  }
}

POST /ocr2/_create/1
{"pageid":"好记性使用手册不如烂笔头感叹号博客园", "text":"好记性使用手册不如烂笔头感叹号博客园"}

POST /ocr2/_create/2
{"pageid":"好记性使用手川不如烂笔头感叹号博客园", "text":"好记性使用手册不如烂笔头感叹号博客园"}

POST /ocr2/_create/3
{"pageid":"好记性使用手川不如烂笔头感叹号博客园", "text":"好记性使用手川不如烂笔头感叹号博客园"}

POST /ocr2/_search
{
  "suggest": {
    "my-suggestion": {
      "prefix": "好记性",
      "completion": {
        "field": "pageid"
      }
    }
  }
}

# result，从结果可见，前缀匹配结果较为理想，index中的数据都得到了匹配
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "suggest" : {
    "my-suggestion" : [
      {
        "text" : "好记性",
        "offset" : 0,
        "length" : 3,
        "options" : [
          {
            "text" : "好记性使用手册不如烂笔头感叹号博客园",
            "_index" : "ocr2",
            "_type" : "_doc",
            "_id" : "1",
            "_score" : 1.0,
            "_source" : {
              "pageid" : "好记性使用手册不如烂笔头感叹号博客园",
              "text" : "好记性使用手册不如烂笔头感叹号博客园"
            }
          },
          {
            "text" : "好记性使用手川不如烂笔头感叹号博客园",
            "_index" : "ocr2",
            "_type" : "_doc",
            "_id" : "2",
            "_score" : 1.0,
            "_source" : {
              "pageid" : "好记性使用手川不如烂笔头感叹号博客园",
              "text" : "好记性使用手册不如烂笔头感叹号博客园"
            }
          },
          {
            "text" : "好记性使用手川不如烂笔头感叹号博客园",
            "_index" : "ocr2",
            "_type" : "_doc",
            "_id" : "3",
            "_score" : 1.0,
            "_source" : {
              "pageid" : "好记性使用手川不如烂笔头感叹号博客园",
              "text" : "好记性使用手川不如烂笔头感叹号博客园"
            }
          }
        ]
      }
    ]
  }
}

POST /ocr2/_search
{
   "suggest": {
    "my-suggestion": {
      "text": "使用手川",
      "term": {
        "field": "text",
        "suggest_mode": "always"
      }
    }
  }
}

# result
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "suggest" : {
    "my-suggestion" : [
      {
        "text" : "用手",
        "offset" : 1,
        "length" : 2,
        "options" : [ ]
      },
      {
        "text" : "川",
        "offset" : 3,
        "length" : 1,
        "options" : [ ]
      }
    ]
  }
}

POST /ocr2/_search
{
   "suggest": {
    "my-suggestion": {
      "text": "使用手川",
      "phrase": {
        "field": "text"
      }
    }
  }
}

# result
{
  "took" : 1,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 0,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "suggest" : {
    "my-suggestion" : [
      {
        "text" : "使用手川",
        "offset" : 0,
        "length" : 4,
        "options" : [ ]
      }
    ]
  }
}