Allowing case-insensitive search with snowball_analyzer in Elasticsearch

Question

First of all I'm completly new to ES. I created ES search criteria below for searching items which works fine but what I now need is, I want to turn make field into case-insensitive so that the search result would be the same for hello, HeLlo, HELLO so on.

I've read post below couldn't quiet apply to my example below because of my very limited knowledge:

• Case insensitivity does not work
• Elasticsearch Map case insensitive to not_analyzed documents
• Elasticsearch Snowball Analyzer wants exact word

Removing not_analyzed from make doesn't help.

'indexes' => [
    'my_project' => [
        'client' => 'default',
        'index_name' => 'hello',
        'settings' => [
            'index' => [
                'analysis' => [
                    'analyzer' => [
                        'snowball_analyzer' => [
                            'type' => 'snowball',
                            'language' => 'English',
                        ],
                    ],
                ],
            ],
        ],
        'types' => [
            'item' => [
                'mappings' => [
                    'uuid' => ['type' => 'string', 'index' => 'not_analyzed'],
                    'name' => ['type' => 'string', 'boost' => 8, 'analyzer' => 'snowball_analyzer'],
                    'make' => ['type' => 'string', 'index' => 'not_analyzed'],
                ]
            ],
        ],
    ],
],

These is the query that I created:

1

{
  "query": {
    "filtered": {
      "query": {
        "bool": {
          "must": [
            {
              "term": {
                "make": "HeLlo"
              }
            }
          ]
        }
      }
    }
  }
}

Answer 1

I went thru the answer in the first link I posted with my eyes open this time and it solved my problem too so my case-insensitive working example is:

{
  "query": {
    "filtered": {
      "query": {
        "bool": {
          "must": [
            {
               "query_string": {
                  "query": "HeLlo*"
                }
            }
          ]
        }
      }
    }
  }
}

Answer 2

You have to add the "lowercase" filter. Here is an extract for a similar configuration I use:

settings:
    index:
        analysis:
            analyzer:
                custom_search_analyzer:
                    type: custom
                    tokenizer: standard
                    filter: [stopwords, asciifolding ,lowercase, snowball, elision, worddelimiter]

In your case, I guess you should change like this:

...                    
'settings' => [
    'index' => [
        'analysis' => [
            'analyzer' => [
                'snowball_analyzer' => [
                    'type' => 'snowball',
                    'language' => 'English',
                    'filter' => [ 'lowercase' ]
                ],
            ],
        ],
    ],
],                        
...