筛选ID值

我在使用ID值筛选字段时遇到了一个问题,不确定这是如何发生的,下面是映射和一个示例。

添加新用户后可以看到 primary_user 设置为 AWBFyulclsp0PJbvPiuB 使用将找不到它 filter 除非 keyword 在筛选器请求中使用。 这只会发生在ID的值上。 这种行为的根本原因是什么?

   GET users/_mapping/

    Response:
    {
     ...
     ...
     "primary_user": {
                "type": "text",
                "fields": {
                  "keyword": {
                    "type": "keyword",
                    "ignore_above": 256
                  }
                }
              }
    }
------
    POST users/user
    {
      "primary_user": "AWBFyulclsp0PJbvPiuB"
    }

    Response:
    {
      "_index": "users",
      "_type": "user",
      "_id": "AWIaOFgQmedTIIkbtGPG",
      "_version": 1,
      "result": "created",
      "_shards": {
        "total": 2,
        "successful": 1,
        "failed": 0
      },
      "created": true
    }
------
    GET users/user/_search
    {
      "query": {
        "bool": {
          "filter": {
            "term": {
              "primary_user": "AWBFyulclsp0PJbvPiuB"
            }
          }
        }
      }
    }
    Response:
    {
      "took": 0,
      "timed_out": false,
      "_shards": {
        "total": 5,
        "successful": 5,
        "failed": 0
      },
      "hits": {
        "total": 0,
        "max_score": null,
        "hits": []
      }
}
------
    GET users/user/_search
    {
      "query": {
        "bool": {
          "filter": {
            "term": {
              "primary_user.keyword": "AWBFyulclsp0PJbvPiuB"
            }
          }
        }
      }
    }

    Response:
    {
        "_index": "users",
        "_type": "user",
        "_id": "AWIaOFgQmedTIIkbtGPG",
        "_score": 0,
        "_source": {
          "primary_user": "AWBFyulclsp0PJbvPiuB"
        }
      }