六十二、Elasticsearch索引管理-定制化自己的dyna

1、定制dynamic策略

（1）true：遇到陌生字段，就进行dynamic mapping

（2）遇到陌生字段，就忽略

（3）strict: 遇到陌生字段，就报错

实例

PUT /my_index
{
  "mappings": {
    "my_type": {
      "dynamic" : "strict",
      "properties": {
        "title" : {
          "type": "text"
        },
        "address" : {
          "type": "object",
          "dynamic" : "true"
        } 
      }
    }
  }
}

创建了一个只能有title和address字段的type。因为dynamic：strict。而address里面可以有任意字段，因为dynamic：true

Demo1

PUT /my_index/my_type/1
{
  "title" : "my article",
  "content" : "this is my article",
  "address" : {
    "province" : "guangdong",
    "city" : "guangzhou"
  }
}

结果

{
  "error": {
    "root_cause": [
      {
        "type": "strict_dynamic_mapping_exception",
        "reason": "mapping set to strict, dynamic introduction of [content] within [my_type] is not allowed"
      }
    ],
    "type": "strict_dynamic_mapping_exception",
    "reason": "mapping set to strict, dynamic introduction of [content] within [my_type] is not allowed"
  },
  "status": 400
}

报错了，说type是strict_dynamic。没有content。

Demo2，删除content

PUT /my_index/my_type/1
{
  "title" : "my article",
  "address" : {
    "province" : "guangdong",
    "city" : "guangzhou",
    "area" : "heheda"
  }
}

结果：

{
  "_index": "my_index",
  "_type": "my_type",
  "_id": "1",
  "_version": 1,
  "result": "created",
  "_shards": {
    "total": 2,
    "successful": 1,
    "failed": 0
  },
  "created": true
}

查看刚才生成的mapping是什么样的？
GET /my_index/_mapping/my_type/

{
  "my_index": {
    "mappings": {
      "my_type": {
        "dynamic": "strict",
        "properties": {
          "address": {
            "dynamic": "true",
            "properties": {
              "area": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword",
                    "ignore_above": 256
                  }
                }
              },
              "city": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword",
                    "ignore_above": 256
                  }
                }
              },
              "province": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword",
                    "ignore_above": 256
                  }
                }
              }
            }
          },
          "title": {
            "type": "text"
          }
        }
      }
    }
  }
}

2、定制dynamic mapping策略

（1）date_detection
默认会按照一定格式识别date，比如yyyy-MM-dd。但是如果某个field先过来一个2017-01-05的值，就会被自动dynamic mapping成date类型，后面如果再来一个比如“hello world”这种非date格式的value，就会报错。

可以手动关闭某个type的date_detection，如果有需要，自己手动指定某个field为date类型。

PUT /my_index/_mapping/my_type
{
  "date_detection": false
}

（2）定制自己的dynamic mapping template（type level）

PUT /my_index2
{
  "mappings": {
    "my_type": {
      "dynamic_templates": [
        {
          "en": {
            "match":              "*_en", 
            "match_mapping_type": "string",
            "mapping": {
                "type":           "string",
                "analyzer":       "english"
            }
          }
        }
      ]
    }
  }
}

新增两条数据

PUT /my_index2/my_type/1
{
  "title": "this is my first article"
}

PUT /my_index2/my_type/2
{
  "title_en": "this is my first article"
}

进行查询

GET /my_index2/my_type/_search
{
  "query": {
    "match": {
      "title": "is"
    }
  }
}

结果

{
  "took": 98,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 1,
    "max_score": 0.2824934,
    "hits": [
      {
        "_index": "my_index2",
        "_type": "my_type",
        "_id": "1",
        "_score": 0.2824934,
        "_source": {
          "title": "this is my first article"
        }
      }
    ]
  }
}

可以查出记录

GET /my_index2/my_type/_search
{
  "query": {
    "match": {
      "titl_en": "is"
    }
  }
}

结果

{
  "took": 1,
  "timed_out": false,
  "_shards": {
    "total": 5,
    "successful": 5,
    "failed": 0
  },
  "hits": {
    "total": 0,
    "max_score": null,
    "hits": []
  }
}

查询不出结果

title没有匹配到任何的dynamic模板，默认就是standard分词器，不会过滤停用词，is会进入倒排索引，用is来搜索是可以搜索到的

title_en匹配到了dynamic模板，就是English分词器，会过滤停用词，is这种停用词就会被过滤掉，用is来搜索就搜索不到了。

（3）定制自己的default mapping template（index level）

PUT /my_index
{
    "mappings": {
        "_default_": {
            "_all": { "enabled":  false }
        },
        "blog": {
            "_all": { "enabled":  true  }
        }
    }
}

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