ElasticSearch：聚合过滤

Question

为简单起见，假设我在弹性中有 3 行的索引：

{"id": 1, "tags": ["t1", "t2", "t3"]}, 
{"id": 2, "tags": ["t1", "t4", "t5"]}

我需要通过一些标签聚合而不返回匹配文档中其他标签的结果：

{
  "aggs": {
    "tags": {
      "terms": {"field": "tags"}
    }
  },
  "query": {
    "bool": {
      "filter": [
        {
          "terms": {"tags": ["t1", "t2"]}
        }
      ]
    }
  }
}

# RESULT
{
    "aggregations": {
        "tags": {
            "buckets": [
                {"doc_count": 2, "key": "t1"},
                {"doc_count": 1, "key": "t2"},
                {"doc_count": 1, "key": "t3"},  # should be removed by filter
                {"doc_count": 1, "key": "t4"},  # should be removed by filter
                {"doc_count": 1, "key": "t5"},  # should be removed by filter
            ],
        }
    },
    "hits": {
        "hits": [],
        "max_score": 0.0,
        "total": 2
    },
}

如何（也许）后过滤这个结果？

因为在索引中有 3 行的情况下，这只有 3 个额外的项目（t3、t4、t5）。但在实际情况下，我的索引中有超过 200K 行，这太可怕了！我需要按 50 个标签聚合，但我得到的结果超过 1K 个标签。

Answer 1

假设您的 Elasticsearch 版本支持它，我应该对术语聚合使用“包含”属性。您的查询应如上：

POST /test/_search
{
  "aggs": {
    "tags": {
      "terms": {"field": "tags",  "include": ["t1", "t2"]}
    }
  },
  "query": {
    "bool": {
      "filter": [
        {
          "terms": {"tags": ["t1", "t2"]}
        }
      ]
    }
  }
}

```