ElasticSearch修改Mapping字段

ES在建好索引后不能再修改Mapping 了，这时候如果要改的话只能新建一个字段，如下所示把logMesssage是text类型，新建一个logMessage.row字段，类型是keyword

PUT prn-/_mapping/prnformat
{
  "properties": {
    "logMessage": {
      "type": "text",
      "fields": {
        "raw": { 
          "type":  "keyword"
        }
      }
    }
  }
}

来源：https://discuss.elastic.co/t/how-to-make-a-field-aggregatable-in-kibana/90470/9