CODEWITHSUNDEEP
elasticsearch
F.Wigarde
F.Wigarde

Reputation: 45

ElasticSearch returning no results

I've been handed a project from a coworker that resigned and without any documentation I'm finding it quite hard to grasp what's wrong with my ElasticSearch results.

If i search the word 'nik' on our e-commerce site i get 4 results:

{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 4,
      "relation" : "eq"
    },
    "max_score" : 25.30471,
    "hits" : [
      {
        "_index" : "elineutv415",
        "_type" : "_doc",
        "_id" : "100500102__sv",
        "_score" : 25.30471,
        "_source" : {
          "IdDim1" : "",
          "D22301" : "100500102",
          "D22302" : "D850Nikon",
          "IdLang" : "sv",
          "D22311" : ""
        }
      },
      {
        "_index" : "elineutv415",
        "_type" : "_doc",
        "_id" : "100500103__sv",
        "_score" : 25.30471,
        "_source" : {
          "IdDim1" : "",
          "D22301" : "100500103",
          "D22302" : "D850Nikon",
          "IdLang" : "sv",
          "D22311" : ""
        }
      },
      {
        "_index" : "elineutv415",
        "_type" : "_doc",
        "_id" : "100500100__sv",
        "_score" : 24.19808,
        "_source" : {
          "IdDim1" : "",
          "D22301" : "100500100",
          "D22302" : "NikonD850",
          "IdLang" : "sv",
          "D22311" : ""
        }
      },
      {
        "_index" : "elineutv415",
        "_type" : "_doc",
        "_id" : "100500101__sv",
        "_score" : 24.19808,
        "_source" : {
          "IdDim1" : "",
          "D22301" : "100500101",
          "D22302" : "NikonD850",
          "IdLang" : "sv",
          "D22311" : ""
        }
      }
    ]
  }
}

However if I search 'D850' or '850' in otherwise the exact same query, I get no results. Even tho the searchstring is in the fields that I'm searching. Any ideas what I'm missing here?

Below is my query

{"size": 500, "query": { "bool": { "must": {  "multi_match": { "query": "nik", "fields": ["D22302^3", "D22301^2", "D22311^1"]}},"filter": { "term":{ "IdLang.keyword": "sv"}}}}}

My mapping

{
   "elineutv415": {
      "mappings": {
         "properties": {
            "D22301": {
               "type": "text",
               "fields": {
                  "keyword": {
                     "type": "keyword",
                     "ignore_above": 256
                  }
               }
            },
            "D22302": {
               "type": "text",
               "analyzer": "ngram_analyzer"
            },
            "D22311": {
               "type": "text",
               "fields": {
                  "keyword": {
                     "type": "keyword",
                     "ignore_above": 256
                  }
               }
            },
            "IdDim1": {
               "type": "text",
               "fields": {
                  "keyword": {
                     "type": "keyword",
                     "ignore_above": 256
                  }
               }
            },
            "IdLang": {
               "type": "text",
               "fields": {
                  "keyword": {
                     "type": "keyword",
                     "ignore_above": 256
                  }
               }
            }
         }
      }
   }
}

Index settings

{
  "elineutv415": {
    "settings": {
      "index": {
        "max_ngram_diff": "11",
        "number_of_shards": "1",
        "provided_name": "elineutv415",
        "creation_date": "1621850814863",
        "analysis": {
          "analyzer": {
            "ngram_analyzer": {
              "filter": [
                "lowercase"
              ],
              "type": "custom",
              "tokenizer": "ngram_tokenizer"
            }
          },
          "tokenizer": {
            "ngram_tokenizer": {
              "token_chars": [
                "letter",
                "punctuation",
                "symbol"
              ],
              "min_gram": "3",
              "type": "ngram",
              "max_gram": "8"
            }
          }
        },
        "number_of_replicas": "1",
        "uuid": "_DT9ytVSSwKPSWCOsFTp1Q",
        "version": {
          "created": "7030199"
        }
      }
    }
  }
}

Upvotes: 0

Views: 321

Answers (1)

Bhavya
Bhavya

Reputation: 16172

You have set "max_gram":3, due to which the maximum token length is set to 3. Due to this, there are no tokens generated for D850 OR 850.

Adding a working example with index mapping, search query, and search result

Index Mapping:

{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_analyzer": {
          "tokenizer": "my_tokenizer",
          "filter": "lowercase"
        }
      },
      "tokenizer": {
        "my_tokenizer": {
          "type": "ngram",
          "min_gram": 3,
          "max_gram": 8,                 // note this
          "token_chars": [
            "letter",
            "digit"
          ]
        }
      }
    },
    "max_ngram_diff": 10
  },
  "mappings": {
    "properties": {
      "D22302": {
        "type": "text",
        "analyzer": "my_analyzer"
      }
    }
  }
}

Index Data:

{
  "IdDim1": "",
  "D22301": "100500102",
  "D22302": "D850Nikon",
  "IdLang": "sv",
  "D22311": ""
}
{
  "IdDim1": "",
  "D22301": "100500103",
  "D22302": "D850Nikon",
  "IdLang": "sv",
  "D22311": ""
}
{
  "IdDim1": "",
  "D22301": "100500100",
  "D22302": "NikonD850",
  "IdLang": "sv",
  "D22311": ""
}
{
  "IdDim1": "",
  "D22301": "100500101",
  "D22302": "NikonD850",
  "IdLang": "sv",
  "D22311": ""
}

Search Query:

{
  "size": 500,
  "query": {
    "bool": {
      "must": {
        "multi_match": {
          "query": "850",
          "fields": [
            "D22302^3",
            "D22301^2",
            "D22311^1"
          ]
        }
      },
      "filter": {
        "term": {
          "IdLang.keyword": "sv"
        }
      }
    }
  }
}

Search Result:

"hits": [
      {
        "_index": "67638785",
        "_type": "_doc",
        "_id": "1",
        "_score": 0.31608155,
        "_source": {
          "IdDim1": "",
          "D22301": "100500102",
          "D22302": "D850Nikon",
          "IdLang": "sv",
          "D22311": ""
        }
      },
      {
        "_index": "67638785",
        "_type": "_doc",
        "_id": "2",
        "_score": 0.31608155,
        "_source": {
          "IdDim1": "",
          "D22301": "100500103",
          "D22302": "D850Nikon",
          "IdLang": "sv",
          "D22311": ""
        }
      },
      {
        "_index": "67638785",
        "_type": "_doc",
        "_id": "3",
        "_score": 0.31608155,
        "_source": {
          "IdDim1": "",
          "D22301": "100500100",
          "D22302": "NikonD850",
          "IdLang": "sv",
          "D22311": ""
        }
      },
      {
        "_index": "67638785",
        "_type": "_doc",
        "_id": "4",
        "_score": 0.31608155,
        "_source": {
          "IdDim1": "",
          "D22301": "100500101",
          "D22302": "NikonD850",
          "IdLang": "sv",
          "D22311": ""
        }
      }
    ]

Upvotes: 2

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