Sharding capability

[BafS]

It would be great to have more information about sharding/using multiple databases.

Doctrine uses a ShardManager interface to get the right connection (using the distribution value) implicitly. It is also possible to do it explicitly to get the right entity manager, for example with Symfony:

class UserController extends AbstractController {
    public function index()
    {
        // Explicit way to deal with the "custom" entity manager
        $products = $this->getDoctrine()
            ->getRepository(Product::class, 'customer')
            ->findAll()
        ;
    }
}

This solution could probably be setup easily, it would be nice to have an example in the documentation.

More information:

• https://www.doctrine-project.org/projects/doctrine-dbal/en/2.11/reference/sharding.html
• https://symfony.com/doc/current/doctrine/multiple_entity_managers.html
• https://stackoverflow.com/questions/11463517/using-relationships-with-multiple-entity-managers/11494543#11494543
• https://labs.madisoft.it/doctrine-sharding/
• https://docs.citusdata.com/en/v9.3/sharding/data_modeling.html