ES-illegal_argument_exception报错

查询语句：

POST food-ingredients-ext/_search
{
  "from": 0,
  "size": 20,
  "query": {
    "multi_match": {
      "query": "cake mix",
      "type": "phrase",
      "fields": [
        "manufacture",
        "brand",
        "name"
      ]
    }
  },
  "highlight": {
    "fields": {
      "name": {
        "pre_tags": [
          ""
        ],
        "post_tags": [
          ""
        ]
      }
    }
  },
  "sort": [
    {
      "name": {
        "order": "asc"
      },
      "_score": {
        "order": "desc"
      }
    }
  ]
}

报错：

{
  "error" : {
    "root_cause" : [
      {
        "type" : "illegal_argument_exception",
        "reason" : "Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."
      }
    ],
    "type" : "search_phase_execution_exception",
    "reason" : "all shards failed",
    "phase" : "query",
    "grouped" : true,
    "failed_shards" : [
      {
        "shard" : 0,
        "index" : "food-ingredients-ext",
        "node" : "XBz2-lMTTHaljuXUKeWzgw",
        "reason" : {
          "type" : "illegal_argument_exception",
          "reason" : "Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."
        }
      }
    ],
    "caused_by" : {
      "type" : "illegal_argument_exception",
      "reason" : "Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [name] in order to load field data by uninverting the inverted index. Note that this can use significant memory.",
      "caused_by" : {
        "type" : "illegal_argument_exception",
        "reason" : "Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [name] in order to load field data by uninverting the inverted index. Note that this can use significant memory."
      }
    }
  },
  "status" : 400
}

原因分析：text字段作为一个整体，默认没有索引。不过text分词之后的keyword是有索引的，因而可以对name.keyword进行聚合。

POST food-ingredients-ext/_search
{
  "from": 0,
  "size": 20,
  "query": {
    "multi_match": {
      "query": "cake mix",
      "type": "phrase",
      "fields": [
        "manufacture",
        "brand",
        "name"
      ]
    }
  },
  "highlight": {
    "fields": {
      "name": {
        "pre_tags": [
          ""
        ],
        "post_tags": [
          ""
        ]
      }
    }
  },
  "sort": [
    {
      "name.keyword": {
        "order": "asc"
      },
      "_score": {
        "order": "desc"
      }
    }
  ]
}