es進行聚合操作時提示Fielddata is disabled on text fields by default

根據es官網的文檔執行

GET /megacorp/employee/_search
{
  "aggs": {
    "all_interests": {
      "terms": { "field": "interests" }
    }
  }
}

• 
  

這個例子時，報錯

{
  "error": {
    "root_cause": [
      {
        "type": "illegal_argument_exception",
        "reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [interests] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory."
      }
    ],
    "type": "search_phase_execution_exception",
    "reason": "all shards failed",
    "phase": "query",
    "grouped": true,
    "failed_shards": [
      {
        "shard": 0,
        "index": "megacorp",
        "node": "-Md3f007Q3G6HtdnkXoRiA",
        "reason": {
          "type": "illegal_argument_exception",
          "reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [interests] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory."
        }
      }
    ],
    "caused_by": {
      "type": "illegal_argument_exception",
      "reason": "Fielddata is disabled on text fields by default. Set fielddata=true on [interests] in order to load fielddata in memory by uninverting the inverted index. Note that this can however use significant memory."
    }
  },
  "status": 400
}

• 
  

搜了一下應該是5.x後對排序，聚合這些操作用單獨的數據結構(fielddata)緩存到內存裏了，需要單獨開啓，官方解釋在此fielddata

簡單來說就是在聚合前執行如下操作

PUT megacorp/_mapping/employee/
{
  "properties": {
    "interests": { 
      "type":     "text",
      "fielddata": true
    }
  }
}

•