When should you use text, keyword or both?

Question

IT Interview Practice · Accepted Answer

Use `text` when you want to find words inside a value. Use `keyword` when you need the whole value for filtering, sorting or grouping.

## Compare the same title

Imagine the product title `Blue Shoes`. With a text analyzer that splits words and lowercases them, it produces `blue` and `shoes`. A search for `shoes` can find that title.

A keyword representation keeps the value as one term, subject to any configured normalizer. It is useful when asking for the entire title or grouping products by that value.

## Support both operations

This mapping fragment defines two indexed representations:

```json
{
  "properties": {
    "title": {
      "type": "text",
      "fields": { "raw": { "type": "keyword" } }
    }
  }
}
```

Search words on `title`; sort or aggregate whole titles on `title.raw`. A multi-field means indexing the same input in more than one way, not sending two copies in every document.

## Keep the extra cost intentional

Both representations require indexing and storage. For a status such as `published`, keyword alone may be enough. For grouping whole titles, prefer the keyword field rather than enabling text fielddata, which loads analyzed terms for such operations and can consume substantial memory.

[Official documentation](https://www.elastic.co/docs/reference/elasticsearch/mapping-reference/text).

Compare the same title

Support both operations

Keep the extra cost intentional

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