The put mapping API requires an existing index. The following create index API request creates the publications index with no mapping.

PUT /publications

The following put mapping API request adds title, a new text field, to the publications index.

PUT /publications/_mapping
{
  "properties": {
    "title":  { "type": "text"}
  }
}

The PUT mapping API can be applied to multiple indices with a single request. For example, we can update the twitter-1 and twitter-2 mappings at the same time:

# Create the two indices
PUT /twitter-1
PUT /twitter-2

# Update both mappings
PUT /twitter-1,twitter-2/_mapping 
{
  "properties": {
    "user_name": {
      "type": "text"
    }
  }
}

You can use the put mapping API to add new properties to an existing object field. To see how this works, try the following example.

Use the create index API to create an index with the name object field and an inner first text field.

PUT /my_index
{
  "mappings": {
    "properties": {
      "name": {
        "properties": {
          "first": {
            "type": "text"
          }
        }
      }
    }
  }
}

Use the put mapping API to add a new inner last text field to the name field.

PUT /my_index/_mapping
{
  "properties": {
    "name": {
      "properties": {
        "last": {
          "type": "text"
        }
      }
    }
  }
}

Use the get mapping API to verify your changes.

GET /my_index/_mapping

The API returns the following response:

{
  "my_index" : {
    "mappings" : {
      "properties" : {
        "name" : {
          "properties" : {
            "first" : {
              "type" : "text"
            },
            "last" : {
              "type" : "text"
            }
          }
        }
      }
    }
  }
}

Multi-fields let you index the same field in different ways. You can use the put mapping API to update the fields mapping parameter and enable multi-fields for an existing field.

To see how this works, try the following example.

Use the create index API to create an index with the city text field.

PUT /my_index
{
  "mappings": {
    "properties": {
      "city": {
        "type": "text"
      }
    }
  }
}

While text fields work well for full-text search, keyword fields are not analyzed and may work better for sorting or aggregations.

Use the put mapping API to enable a multi-field for the city field. This request adds the city.raw keyword multi-field, which can be used for sorting.

PUT /my_index/_mapping
{
  "properties": {
    "city": {
      "type": "text",
      "fields": {
        "raw": {
          "type": "keyword"
        }
      }
    }
  }
}

Use the get mapping API to verify your changes.

GET /my_index/_mapping

The API returns the following response:

{
  "my_index" : {
    "mappings" : {
      "properties" : {
        "city" : {
          "type" : "text",
          "fields" : {
            "raw" : {
              "type" : "keyword"
            }
          }
        }
      }
    }
  }
}

The documentation for each mapping parameter indicates whether you can update it for an existing field using the put mapping API. For example, you can use the put mapping API to update the ignore_above parameter.

To see how this works, try the following example.

Use the create index API to create an index containing a user_id keyword field. The user_id field has an ignore_above parameter value of 20.

PUT /my_index
{
  "mappings": {
    "properties": {
      "user_id": {
        "type": "keyword",
        "ignore_above": 20
      }
    }
  }
}

Use the put mapping API to change the ignore_above parameter value to 100.

PUT /my_index/_mapping
{
  "properties": {
    "user_id": {
      "type": "keyword",
      "ignore_above": 100
    }
  }
}

Use the get mapping API to verify your changes.

GET /my_index/_mapping

The API returns the following response:

{
  "my_index" : {
    "mappings" : {
      "properties" : {
        "user_id" : {
          "type" : "keyword",
          "ignore_above" : 100
        }
      }
    }
  }
}

Except for supported mapping parameters, you can’t change the mapping or field type of an existing field. Changing an existing field could invalidate data that’s already indexed.

If you need to change the mapping of a field, create a new index with the correct mapping and reindex your data into that index.

To see how this works, try the following example.

Use the create index API to create the users index with the user_id field with the long field type.

PUT /users
{
  "mappings" : {
    "properties": {
      "user_id": {
        "type": "long"
      }
    }
  }
}

Use the index API to index several documents with user_id field values.

POST /users/_doc?refresh=wait_for
{
    "user_id" : 12345
}

POST /users/_doc?refresh=wait_for
{
    "user_id" : 12346
}

To change the user_id field to the keyword field type, use the create index API to create the new_users index with the correct mapping.

PUT /new_users
{
  "mappings" : {
    "properties": {
      "user_id": {
        "type": "keyword"
      }
    }
  }
}

Use the reindex API to copy documents from the users index to the new_users index.

POST /_reindex
{
  "source": {
    "index": "users"
  },
  "dest": {
    "index": "new_users"
  }
}

The API returns the following response:

{
  "took": 147,
  "timed_out": false,
  "total": 2,
  "updated": 0,
  "created": 2,
  "deleted": 0,
  "batches": 1,
  "version_conflicts": 0,
  "noops": 0,
  "retries": {
    "bulk": 0,
    "search": 0
  },
  "throttled_millis": 0,
  "requests_per_second": -1.0,
  "throttled_until_millis": 0,
  "failures" : [ ]
}

Renaming a field would invalidate data already indexed under the old field name. Instead, add an alias field to create an alternate field name.

For example, use the create index API to create an index with the user_identifier field.

PUT /my_index
{
  "mappings": {
    "properties": {
      "user_identifier": {
        "type": "keyword"
      }
    }
  }
}

Use the put mapping API to add the user_id field alias for the existing user_identifier field.

PUT /my_index/_mapping
{
  "properties": {
    "user_id": {
      "type": "alias",
      "path": "user_identifier"
    }
  }
}

Use the get mapping API to verify your changes.

GET /my_index/_mapping

The API returns the following response:

{
  "my_index" : {
    "mappings" : {
      "properties" : {
        "user_id" : {
          "type" : "alias",
          "path" : "user_identifier"
        },
        "user_identifier" : {
          "type" : "keyword"
        }
      }
    }
  }
}