Uppercase token filter

The uppercase token filter is used to convert all tokens (words) to uppercase during analysis.

Example

The following example request creates a new index named uppercase_example and configures an analyzer with an uppercase filter:

  1. PUT /uppercase_example
  2. {
  3.   "settings": {
  4.     "analysis": {
  5.       "filter": {
  6.         "uppercase_filter": {
  7.           "type": "uppercase"
  8.         }
  9.       },
  10.       "analyzer": {
  11.         "uppercase_analyzer": {
  12.           "type": "custom",
  13.           "tokenizer": "standard",
  14.           "filter": [
  15.             "lowercase",
  16.             "uppercase_filter"
  17.           ]
  18.         }
  19.       }
  20.     }
  21.   }
  22. }

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Generated tokens

Use the following request to examine the tokens generated using the analyzer:

  1. GET /uppercase_example/_analyze
  2. {
  3.   "analyzer": "uppercase_analyzer",
  4.   "text": "OpenSearch is powerful"
  5. }

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The response contains the generated tokens:

  1. {
  2.   "tokens": [
  3.     {
  4.       "token": "OPENSEARCH",
  5.       "start_offset": 0,
  6.       "end_offset": 10,
  7.       "type": "<ALPHANUM>",
  8.       "position": 0
  9.     },
  10.     {
  11.       "token": "IS",
  12.       "start_offset": 11,
  13.       "end_offset": 13,
  14.       "type": "<ALPHANUM>",
  15.       "position": 1
  16.     },
  17.     {
  18.       "token": "POWERFUL",
  19.       "start_offset": 14,
  20.       "end_offset": 22,
  21.       "type": "<ALPHANUM>",
  22.       "position": 2
  23.     }
  24.   ]
  25. }