你有没有找下面的东西？

POST sample_index/_doc
{
  "Account_Name": [
    "machine-name",
    "account-name"
  ]
}

POST sample_index/_update_by_query
{
  "query": {
    "match_all": {}
  },
  "script": {
    "source": "ctx._source['Account_Name'].remove(0)",
    "lang": "painless"
  }
}

GET sample_index/_search

检索后结果：

{
  "took": 892,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1,
    "hits": [
      {
        "_index": "sample_index",
        "_id": "t3RIY4YBnUNkT6fHnBrI",
        "_score": 1,
        "_source": {
          "Account_Name": [
            "account-name"
          ]
        }
      }
    ]
  }
}