How to efficiently detach an entity and it's relationships?

[nitwhiz]

So I have something like this:

#[ORM\Entity(repositoryClass: ActorRepository::class)]
class Actor implements HasEntityAttributes
{
    #[ORM\Id]
    #[ORM\GeneratedValue(strategy: 'CUSTOM')]
    #[ORM\Column(type: 'uuid')]
    #[ORM\CustomIdGenerator(class: 'doctrine.uuid_generator')]
    private ?string $id = null;

    /**
     * @var Collection<int, ActorAttribute>
     */
    #[ORM\OneToMany(mappedBy: 'actor', targetEntity: ActorAttribute::class, cascade: [ 'persist', 'remove' ])]
    private Collection $attributes;
}

If I detach this entity now, it's ActorAttribute entities are still attached. How would I detach "everything related", without having to write a specific detach for every entity?

Just to be sure we don't get a XY-problem here

My main goal is to clear the entity manager, but only remove a (not really small, 16 items) list of entities from the entity manager. I'm dealing with a long-ish running process, batch processing up to ~300.000 rows of data. I observed that the processing rate gets absurdly low (< 10 rows per second), after it gets going with a couple 100 rows per second for the first 5 secs. (i know, "rows per second" is a very esoteric unit, it's just to bring my point across: entity handling gets slow.)

After implementing a clear (with flush before) every X seconds, keeping the other entities around across the clears, i get a pretty consistent processing rate of nearly 100 rows per second.

As keeping the other entities, which aren't to be cleared, around is an absolute PITA, how should I go for this?

[nitwhiz]

So I just stumbled over Transitive persistence / Cascade Operations when researching something completely different and there's something about cascade: detach.

Would that do what I ask for?