// indices/put-mapping.asciidoc:536

[source, php]
----
$params = [
    'index' => 'my_index',
    'body' => [
        'properties' => [
            'user_id' => [
                'type' => 'alias',
                'path' => 'user_identifier',
            ],
        ],
    ],
];
$response = $client->indices()->putMapping($params);
----