Doctrine 2 | Criteria vs DQL | Performance & Usability - doctrine-orm

Question

I was wondering what is the best practice for fetching collections by complex queries in Doctrine 2. I have been using the Cirteria matching functionality, but I want to know if it is usable for large scale databases.
$expr = Criteria::expr();
$criteria = Criteria::create();
$criteria->where(
$expr->andX(
$expr->gte('start', $start),
$expr->lte('end', $end)
)
);
$result = (new ArrayCollection($em->getRepository(Entity::class)->findAll())->matching($criteria);
What is the difference in performace with same filter written in DQL.
$qb = $em->createQueryBuilder();
$qb->select('e')
->from('Entity', 'e')
->where('e.start >= :start')
->andWhere('e.end <= :end')
->setParameters(array('start' => $start, 'end' => $end));
return $qb->getQuery()->getArrayResult();
And a native SQL one.
$rsm = new ResultSetMapping;
$rsm->addEntityResult('Entity', 'e');
$query = $this->_em->createNativeQuery('SELECT * FROM Entity WHERE start >= ? AND end <= ?', $rsm);
$query->setParameter(1, $start);
$query->setParameter(2, $end);
$result = $query->getResult();
I really like the criteria one as it is easy to read and easy to maintain. But is it usable? How does the performace suffer when fetching 1 000, 10 000 or even 100 000 records.
The second question is does the Doctrine Criteria fetches all result and then filters them or does it create the specific query first?
The docs says this, but does it apply to my case?
"Collections have a filtering API that allows to slice parts of data from a collection. If the collection has not been loaded from the database yet, the filtering API can work on the SQL level to make optimized access to large collections."
Doctrine 2 Criteria documentation

Answer 1

The problem is that you are using Criteria to match records after calling findAll() in your Repo. You should use criteria direct over your Repo, not to the array collection.
$criteria = new Criteria();
$criteria->where(Criteria::expr()->gte('legajo', $this->legajoDesde));
$criteria->andWhere(Criteria::expr()->lte('legajo', $this->legajoHasta));
$criteria->andWhere(Criteria::expr()->eq('idOrganizacion', $this->idOrganizacion));
$criteria->orderBy(['legajo' => Criteria::ASC]);
$empleados = $empleadoRepository->matching($criteria);