case insensitive keyword search

my_kws.json

DELETE test

PUT test
{
  "settings": {
    "analysis": {
      "analyzer": {
        "my_case_insensitive_keyword": {
          "type": "custom",
          "char_filter": [],
          "tokenizer": "keyword",
          "filter": [
            "lowercase"
          ]
        }
      }
    }
  },
  "mappings": {
    "_doc": {
      "properties": {
        "my_kw": {
          "type": "text",
          "analyzer": "my_case_insensitive_keyword",
          "fielddata":true
        }
      }
    }
  }
}

PUT test/_doc/abc
{"my_kw":"abc"}

PUT test/_doc/ABC
{"my_kw":"ABC"}

PUT test/_doc/xYz
{"my_kw":"xYz"}

GET test/_search

GET test/_search
{
  "query": {
    "match": {
      "my_kw": "abc"
    }
  }
}

GET test/_search
{
  "query": {
    "match": {
      "my_kw": "ABC"
    }
  }
}

GET test/_search
{
  "size": 0,
  "aggs": {
    "my_kw_count": {
      "cardinality": {
        "field": "my_kw"
      }
    }
  }
}

GET test/_search
{
  "size": 0,
  "aggs": {
    "my_kw_count": {
      "terms": {
        "field": "my_kw"
      }
    }
  }
}