Link indexes?

Question

Doctrine ORM

Here is an example on simple type

A is not that.

Why can't you say so?

<entity name="App\Domain\UserPack\Password\Entity\UserPassword">
        <indexes>
            <index name="search_idx" columns="user"/>
        </indexes>

        <embedded name="id" class="App\Domain\Core\ValueObjects\EntityId" use-column-prefix="false"/>
...
        <many-to-one target-entity="App\Domain\UserPack\User\Entity\User"
                     field="user"
                     inversed-by="passwords"
        >
..
            <join-column name="user_uuid" referenced-column-name="uuid"/>
        </many-to-one>