将 ngrams 与 elasticsearch 一起使用时带回所有相关结果

Question

我用 ngrams 为我的 elasticsearch 索引建立了索引，以便快速进行模糊匹配和前缀搜索。我注意到，如果我在名称字段中搜索包含 "Bob" 的文档，只会得到 name = Bob return 的结果。我希望响应包括名称为 Bob 的文档，但也名称为 Bobbi、Bobbette 等的文档。 Bob 结果应该有一个相对较高的分数。其他不完全匹配的结果仍应出现在结果集中，但分数较低。我如何使用 ngrams 实现此目的？

我正在使用一个非常小的简单索引来测试。索引包含两个文档。

 {
    "_index": "contacts_4",
    "_type": "_doc",
    "_id": "1",
    "_score": 1.0,
    "_source": {
      "full_name": "Bob Smith"
    }
  },
  {
    "_index": "contacts_4",
    "_type": "_doc",
    "_id": "2",
    "_score": 1.0,
    "_source": {
      "full_name": "Bobby Smith"
    }
  }

Answer 1

这是一个工作示例（使用 n-gram 分词器）：

ngram-tokenizer

映射

  PUT my_index
  {
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "filter": [
            "lowercase"
          ],
          "type": "custom",
          "tokenizer": "my_tokenizer"
        }
      },
      "tokenizer": {
        "my_tokenizer": {
          "token_chars": [
            "letter",
            "digit"
          ],
          "min_gram": "3",
          "type": "ngram",
          "max_gram": "4"
        }
      }
    }
  },
  "mappings": {
    "properties": {
      "full_name": {
        "type": "text",
        "analyzer": "my_analyzer",
        "fields": {
          "keyword": {
            "type": "keyword"
          }
        }
      }
    }
  }
}

索引文档

POST my_index/_doc/1
{
  "full_name":"Bob Smith"
}

POST my_index/_doc/2
{
  "full_name":"Bobby Smith"
}

POST my_index/_doc/3
{
  "full_name":"Bobbette Smith"
}

搜索查询

GET my_index/_search
{
  "query": {
    "match": {
      "full_name": "Bob"
    }
  }
}

结果

"hits" : [
  {
    "_index" : "my_index",
    "_type" : "_doc",
    "_id" : "1",
    "_score" : 0.1626403,
    "_source" : {
      "full_name" : "Bob Smith"
    }
  },
  {
    "_index" : "my_index",
    "_type" : "_doc",
    "_id" : "2",
    "_score" : 0.13703513,
    "_source" : {
      "full_name" : "Bobby Smith"
    }
  },
  {
    "_index" : "my_index",
    "_type" : "_doc",
    "_id" : "3",
    "_score" : 0.11085624,
    "_source" : {
      "full_name" : "Bobbette Smith"
    }
  }
]

希望对您有所帮助

将 ngrams 与 elasticsearch 一起使用时带回所有相关结果

Bring back all relevant results when using ngrams with elasticsearch

prefix

n-gram

elasticsearch