Es custom analyzer

Analyzer definition

An analyzer is a wrapper that combines three functions , The three functions are executed in the following order ：

• Character filter Process the initial input string , You can filter out specific characters , Or convert to custom characters
• Word segmentation is The word breaker divides the string into single entries , An parser must have a unique word breaker
• Word unit filter The entries pass through the word unit filter in order , Word unit filters can be modified , Add or remove entries . for example ：lowercase filter , Will convert all letters to lowercase .

Custom Analyzer

  stay analysis Set the character filter in the corresponding position below 、 Word splitters and word unit filters , The format is ：

PUT /my_index
{
    "settings": {
        "analysis": {
            "char_filter": { ...  Character filter  ... },
            "tokenizer":   { ...    Word segmentation is     ... },
            "filter":      { ...    Word unit filter    ... },
            "analyzer":    { ...    analyzer       ... }
        }
    }
} 

Definition in practical application :

{
  "analysis": {
    "tokenizer": {
      "filter": {
        "my_stopwords": {
          "type": "stop",
          "stopwords": [
            "the",
            "a"
          ]
        }
      },
      "trigram_tokenizer": {
        "type": "ngram",
        "min_gram": 1,
        "max_gram": 3,
        "token_chars": [
          "letter",
          "digit"
        ]
      }
    },
    "analyzer": {
      "trigram_analyzer": {
        "tokenizer": "trigram_tokenizer",
        "filter": [
          "lowercase",“my_stopwords”
        ]
      }
    }
  }
}

Define an analyzer trigram_analyzer, Use word splitter tokenizer, use ngram As this unit filter , The character filter only retains letters letter And number digit, And convert to lowercase letters lowercase, Get rid of the and a