normalizer

ノーマライザー

[normalizer]のプロパティは、keywordフィールドに似ていますが、分析チェーンが単一のトークンを生成することを保証します。

[normalizer]は、キーワードのインデックス作成前および[keyword]フィールドがmatchクエリやtermのようなタームレベルのクエリを介して検索される際に適用されます。

[lowercase]というシンプルなノーマライザーがelasticsearchに付属しており、使用できます。カスタムノーマライザーは、分析設定の一部として次のように定義できます。

Python

resp = client.indices.create(
   index="index",
   settings={
   "analysis": {
   "normalizer": {
   "my_normalizer": {
   "type": "custom",
   "char_filter": [],
   "filter": [
   "lowercase",
   "asciifolding"
   ]
   }
   }
   }
   },
   mappings={
   "properties": {
   "foo": {
   "type": "keyword",
   "normalizer": "my_normalizer"
   }
   }
   },
)
print(resp)
resp1 = client.index(
   index="index",
   id="1",
   document={
   "foo": "BÀR"
   },
)
print(resp1)
resp2 = client.index(
   index="index",
   id="2",
   document={
   "foo": "bar"
   },
)
print(resp2)
resp3 = client.index(
   index="index",
   id="3",
   document={
   "foo": "baz"
   },
)
print(resp3)
resp4 = client.indices.refresh(
   index="index",
)
print(resp4)
resp5 = client.search(
   index="index",
   query={
   "term": {
   "foo": "BAR"
   }
   },
)
print(resp5)
resp6 = client.search(
   index="index",
   query={
   "match": {
   "foo": "BAR"
   }
   },
)
print(resp6)

Ruby

response = client.indices.create(
  index: 'index',
  body: {
   settings: {
   analysis: {
   normalizer: {
   my_normalizer: {
   type: 'custom',
   char_filter: [],
   filter: [
   'lowercase',
   'asciifolding'
   ]
   }
   }
   }
   },
   mappings: {
   properties: {
   foo: {
   type: 'keyword',
   normalizer: 'my_normalizer'
   }
   }
   }
  }
)
puts response
response = client.index(
  index: 'index',
  id: 1,
  body: {
   foo: 'BÀR'
  }
)
puts response
response = client.index(
  index: 'index',
  id: 2,
  body: {
   foo: 'bar'
  }
)
puts response
response = client.index(
  index: 'index',
  id: 3,
  body: {
   foo: 'baz'
  }
)
puts response
response = client.indices.refresh(
  index: 'index'
)
puts response
response = client.search(
  index: 'index',
  body: {
   query: {
   term: {
   foo: 'BAR'
   }
   }
  }
)
puts response
response = client.search(
  index: 'index',
  body: {
   query: {
   match: {
   foo: 'BAR'
   }
   }
  }
)
puts response

Js

const response = await client.indices.create({
  index: "index",
  settings: {
   analysis: {
   normalizer: {
   my_normalizer: {
   type: "custom",
   char_filter: [],
   filter: ["lowercase", "asciifolding"],
   },
   },
   },
  },
  mappings: {
   properties: {
   foo: {
   type: "keyword",
   normalizer: "my_normalizer",
   },
   },
  },
});
console.log(response);
const response1 = await client.index({
  index: "index",
  id: 1,
  document: {
   foo: "BÀR",
  },
});
console.log(response1);
const response2 = await client.index({
  index: "index",
  id: 2,
  document: {
   foo: "bar",
  },
});
console.log(response2);
const response3 = await client.index({
  index: "index",
  id: 3,
  document: {
   foo: "baz",
  },
});
console.log(response3);
const response4 = await client.indices.refresh({
  index: "index",
});
console.log(response4);
const response5 = await client.search({
  index: "index",
  query: {
   term: {
   foo: "BAR",
   },
  },
});
console.log(response5);
const response6 = await client.search({
  index: "index",
  query: {
   match: {
   foo: "BAR",
   },
  },
});
console.log(response6);

コンソール

PUT index
{
  "settings": {
   "analysis": {
   "normalizer": {
   "my_normalizer": {
   "type": "custom",
   "char_filter": [],
   "filter": ["lowercase", "asciifolding"]
   }
   }
   }
  },
  "mappings": {
   "properties": {
   "foo": {
   "type": "keyword",
   "normalizer": "my_normalizer"
   }
   }
  }
}
PUT index/_doc/1
{
  "foo": "BÀR"
}
PUT index/_doc/2
{
  "foo": "bar"
}
PUT index/_doc/3
{
  "foo": "baz"
}
POST index/_refresh
GET index/_search
{
  "query": {
   "term": {
   "foo": "BAR"
   }
  }
}
GET index/_search
{
  "query": {
   "match": {
   "foo": "BAR"
   }
  }
}

上記のクエリは、[BÀR]がインデックス作成時とクエリ時の両方で[bar]に変換されるため、ドキュメント1と2に一致します。

コンソール-結果

{
  "took": $body.took,
  "timed_out": false,
  "_shards": {
   "total": 1,
   "successful": 1,
   "skipped" : 0,
   "failed": 0
  },
  "hits": {
   "total" : {
   "value": 2,
   "relation": "eq"
   },
   "max_score": 0.4700036,
   "hits": [
   {
   "_index": "index",
   "_id": "1",
   "_score": 0.4700036,
   "_source": {
   "foo": "BÀR"
   }
   },
   {
   "_index": "index",
   "_id": "2",
   "_score": 0.4700036,
   "_source": {
   "foo": "bar"
   }
   }
   ]
  }
}

また、キーワードがインデックス作成前に変換されるという事実は、集約が正規化された値を返すことを意味します：

Python

resp = client.search(
   index="index",
   size=0,
   aggs={
   "foo_terms": {
   "terms": {
   "field": "foo"
   }
   }
   },
)
print(resp)

Ruby

response = client.search(
  index: 'index',
  body: {
   size: 0,
   aggregations: {
   foo_terms: {
   terms: {
   field: 'foo'
   }
   }
   }
  }
)
puts response

Js

const response = await client.search({
  index: "index",
  size: 0,
  aggs: {
   foo_terms: {
   terms: {
   field: "foo",
   },
   },
  },
});
console.log(response);

コンソール

GET index/_search
{
  "size": 0,
  "aggs": {
   "foo_terms": {
   "terms": {
   "field": "foo"
   }
   }
  }
}

返します

コンソール-結果

{
  "took": 43,
  "timed_out": false,
  "_shards": {
   "total": 1,
   "successful": 1,
   "skipped" : 0,
   "failed": 0
  },
  "hits": {
   "total" : {
   "value": 3,
   "relation": "eq"
   },
   "max_score": null,
   "hits": []
  },
  "aggregations": {
   "foo_terms": {
   "doc_count_error_upper_bound": 0,
   "sum_other_doc_count": 0,
   "buckets": [
   {
   "key": "bar",
   "doc_count": 2
   },
   {
   "key": "baz",
   "doc_count": 1
   }
   ]
   }
  }
}