title: How to change tokenizer in elasticsearch in the existing index
body: <p>I have the following problem:
  I have an index of 30 million documents the mapping as follows:</p>
  
  <pre><code>curl -XPUT localhost:8080/xxxxx/yyyyy/_mapping?pretty=true -d '{"xxxxx":{"_id":{"type":"string","index":"not_analyzed"},"properties":{"content":
  {"type":"string","store":"no"},"title":{"type":"string","index":"no"},"created_date":{"type":"integer","index":"not_analyzed"},"url":
  {"type":"string","index":"not_analyzed"},"author":{"type":"string","index":"no"},"author_url":{"type":"string","index":"no"},"domain":
  {"type":"string","index":"not_analyzed"},"lang":{"type":"string","index":"no"}}}}'
  </code></pre>
  
  <p>Tokenizer is not selected in the settings, so apply a standard.
  I would like to request "facets" to create ranking links(url) in field "content". Unfortunately I can not do that because the standard tokenizer shared links (url) to pieces.
  Question:
  Can an existing index without reindexing change the tokenizer, so that new documents added to the index handle the new tokenizer (uax_url_email) and old documents remain unchanged.</p>
  
  <p>I tried that:</p>
  
  <pre><code>curl -XPUT localhost:8080/xxxxx -d '{
    "settings" : {
      "index": {
        "analysis" :{
          "analyzer": {
            "default": {
              "type" : "custom",
              "tokenizer" : "uax_url_email",
              "filter" : "lowercase"
            }
          }
        }
      }
    }
  }
  '
  </code></pre>
  
  <p>but I get an error:
  <code>{"error": "IndexAlreadyExistsException [[xxxxx] Already exists]", "status": 400}</code></p>
  
  <p>Is there another way to not reindex with query "facets" to create ranking links (url)?</p>
  
  <p>Thank you in advance of any help</p>