Elasticsearch Multi-Term Auto Completion

Question

I'm trying to implement the Multi-Term Auto Completion that's presented here.

Filtering down to the correct documents works, but when aggregating the completion_terms they are not filtered to those that match the current partial query, but instead include all completion_terms from any matched documents.

Here are the mappings:

{
  "mappings": {
    "dynamic" : "false",
    "properties" : {
      "completion_ngrams" : {
        "type" : "text",
        "analyzer" : "completion_ngram_analyzer",
        "search_analyzer" : "completion_ngram_search_analyzer"
      },
      "completion_terms" : {
        "type" : "keyword",
        "normalizer" : "completion_normalizer"
      }
    }
  }
}

Here are the settings:

{
    "settings" : {
      "index" : {
        "analysis" : {
          "filter" : {
            "edge_ngram" : {
              "type" : "edge_ngram",
              "min_gram" : "1",
              "max_gram" : "10"
            }
          },
          "normalizer" : {
            "completion_normalizer" : {
              "filter" : [
                "lowercase",
                "german_normalization"
              ],
              "type" : "custom"
            }
          },
          "analyzer" : {
            "completion_ngram_search_analyzer" : {
              "filter" : [
                "lowercase"
              ],
              "tokenizer" : "whitespace"
            },
            "completion_ngram_analyzer" : {
              "filter" : [
                "lowercase",
                "edge_ngram"
              ],
              "tokenizer" : "whitespace"
            }
          }
        }
      }
    }
  }
}

I'm then indexing data like this:

{
  "completion_terms" : ["Hammer", "Fortis", "Tool", "2000"],
  "completion_ngrams": "Hammer Fortis Tool 2000"
}

Finally, the autocomplete search looks like this:

{
  "query": {
    "bool": {
      "must": [
        {
          "term": {
            "completion_terms": "fortis"
          }
        },
        {
          "term": {
            "completion_terms": "hammer"
          }
        },        
        {
          "match": {
            "completion_ngrams": "too"
          }
        }
      ]
    }
  },
  "aggs": {
    "autocomplete": {
      "terms": {
        "field": "completion_terms",
        "size": 100
      }
    }
  }
}

This correctly returns documents matching the search string "fortis hammer too", but the aggregations include ALL completion terms that are included in any of the matched documents, e.g. for the query above:

"buckets": [
  { "key": "fortis" },
  { "key": "hammer" },
  { "key": "tool" },
  { "key": "2000" },
]

Ideally, I'd expect

"buckets": [
  { "key": "tool" }
]

I could filter out the terms that are already covered by the search query ("fortis" and "hammer" in this case) in the app, but the "2000" doesn't make any sense from a user's perspective, because it doesn't partially match any of the provided search terms.

I understand why this is happening, but I can't think of a solution. Can anyone help?

user_18349156 · Answer

try filters agg please

{
  "query": {
    "bool": {
      "must": [
        {
          "term": {
            "completion_terms": "fortis"
          }
        },
        {
          "term": {
            "completion_terms": "hammer"
          }
        },
        {
          "match": {
            "completion_ngrams": "too"
          }
        }
      ]
    }
  },
  "aggs": {
    "findOuthammerAndfortis": {
      "filters": {
        "filters": {
          "fortis": {
            "term": {
              "completion_terms": "fortis"
            }
          },
          "hammer": {
            "term": {
              "completion_terms": "hammer"
            }
          }
        }
      }
    }
  }
}

Elasticsearch Multi-Term Auto Completion

1 Answers