index_optionsedit

The index_options parameter controls what information is added to the inverted index, for search and highlighting purposes. It accepts the following settings:

docs

Only the doc number is indexed. Can answer the question Does this term exist in this field?

freqs

Doc number and term frequencies are indexed. Term frequencies are used to score repeated terms higher than single terms.

positions

Doc number, term frequencies, and term positions (or order) are indexed. Positions can be used for proximity or phrase queries.

offsets

Doc number, term frequencies, positions, and start and end character offsets (which map the term back to the original string) are indexed. Offsets are used by the unified highlighter to speed up highlighting.

Numeric fields don’t support the index_options parameter any longer.

Analyzed string fields use positions as the default, and all other fields use docs as the default.

PUT my_index
{
  "mappings": {
    "properties": {
      "text": {
        "type": "text",
        "index_options": "offsets"
      }
    }
  }
}

PUT my_index/_doc/1
{
  "text": "Quick brown fox"
}

GET my_index/_search
{
  "query": {
    "match": {
      "text": "brown fox"
    }
  },
  "highlight": {
    "fields": {
      "text": {} 
    }
  }
}

The text field will use the postings for the highlighting by default because offsets are indexed.