Elasticsearch Dynamic Mapping，内容来自 B 站中华石杉 Elasticsearch 顶尖高手系列课程核心知识篇，英文内容来自 Elasticsearch: The Definitive Guide [2.x]。

Dynamic Mapping

https://www.elastic.co/guide/en/elasticsearch/guide/2.x/dynamic-mapping.html

When Elasticsearch encounters a previously unknown field in a document, it uses dynamic mapping to determine the datatype for the field and automatically adds the new field to the type mapping.

dynamic setting 定制 dynamic 策略

• true：遇到陌生字段，就进行dynamic mapping

• false：遇到陌生字段，就忽略

• strict：遇到陌生字段，就报错

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

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

{
  "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
}

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

GET /my_index/_mapping/my_type

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