Symfony & Doctrine 2 / Speed up query - doctrine-orm

Question

I have a problem with query speed after I joined 3 tables. Before speed was 120-500ms. Now it's 1500-5000ms. It's possible to speed up my query?
Here is my query builder:
public function findByCategory($category)
{
$qb = $this->createQueryBuilder('p');
$qb->select('p');
$qb->leftJoin('p.details', 'd');
$qb->leftJoin('p.model', 'm');
$qb->leftJoin('m.category', 'c');
$qb->where('c.id = :category');
$qb->andWhere('d.quantity > 0');
$qb->setParameter('category', $category);
$qb->addOrderBy('p.id', 'DESC');
$qb->setMaxResults(10);
return $qb->getQuery()->useQueryCache(true)->useResultCache(true, 31536000, uniqid())->getResult();
}
and here is formatted query:
SELECT
p0_.id AS id_0,
p0_.title AS title_1,
p0_.url AS url_2,
p0_.description AS description_3,
p0_.views AS views_4,
p0_.price AS price_5,
p0_.is_active AS is_active_6,
p0_.created_at AS created_at_7,
p0_.updated_at AS updated_at_8,
p0_.model_id AS model_id_9,
p0_.details_id AS details_id_10
FROM
products p0_
LEFT JOIN product_details p1_ ON p0_.details_id = p1_.id
LEFT JOIN models m2_ ON p0_.model_id = m2_.id
LEFT JOIN categories c3_ ON m2_.category_id = c3_.id
WHERE
c3_.id = ?
AND p1_.`quantity` > 0
ORDER BY
p0_.id DESC
LIMIT
10
Thanks
EDIT:
Products model:
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="title", type="string", length=255)
*/
private $title;
/**
* #var string
*
* #ORM\Column(name="url", type="string", length=255)
*/
private $url;
/**
* #var string
*
* #ORM\Column(name="description", type="text", nullable=true)
*/
private $description;
/**
* #var int
*
* #ORM\Column(name="views", type="bigint", nullable=true)
*/
private $views;
/**
* #ORM\ManyToOne(targetEntity="Models")
* #ORM\JoinColumn(name="model_id", referencedColumnName="id")
*/
private $model;
/**
* #ORM\OneToOne(targetEntity="ProductDetails", cascade={"persist"})
* #ORM\JoinColumn(name="details_id", referencedColumnName="id")
*/
private $details;
/**
* #var File
*
* #ORM\OneToMany(targetEntity="ProductImages", mappedBy="product", cascade={"persist"})
*
*/
private $images;
/**
* #var File
*
* #ORM\OneToMany(targetEntity="Cart", mappedBy="productId", cascade={"persist"})
*
*/
private $cart;
/**
* #var string
*
* #ORM\Column(name="price", type="integer", length=255)
*/
private $price;
/**
* #var bool
*
* #ORM\Column(name="is_active", type="boolean")
*/
private $isActive;
/**
* created Time/Date
*
* #var \DateTime
*
* #ORM\Column(name="created_at", type="datetime", nullable=false)
*/
protected $createdAt;
/**
* updated Time/Date
*
* #var \DateTime
*
* #ORM\Column(name="updated_at", type="datetime", nullable=false)
*/
protected $updatedAt;
ProductDetail model:
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="`processor`", type="string", length=255, nullable=true)
*/
private $processor;
/**
* #var string
*
* #ORM\Column(name="`graphic_card`", type="string", length=255, nullable=true)
*/
private $graphicCard;
/**
* #var string
*
* #ORM\Column(name="`release_year`", type="string", length=4, nullable=true)
*/
private $releaseYear;
/**
* #var string
*
* #ORM\Column(name="`ram`", type="string", length=255, nullable=true)
*/
private $ram;
/**
* #var string
*
* #ORM\Column(name="`ssd`", type="string", length=255, nullable=true)
*/
private $ssd;
/**
* #var string
*
* #ORM\Column(name="`hdd`", type="string", length=255, nullable=true)
*/
private $hdd;
/**
* #var string
*
* #ORM\Column(name="`battery`", type="string", length=255, nullable=true)
*/
private $battery;
/**
* #var string
*
* #ORM\Column(name="`color`", type="string", length=255, nullable=true)
*/
private $color;
/**
* #var string
*
* #ORM\Column(name="`accessories`", type="string", length=255, nullable=true)
*/
private $accessories;
/**
* #var string
*
* #ORM\Column(name="`guarantee`", type="string", length=255, nullable=true)
*/
private $guarantee;
/**
* #var string
*
* #ORM\Column(name="`condition`", type="string", length=255)
*/
private $condition;
/**
* #var string
*
* #ORM\Column(name="`quantity`", type="string", length=255)
*/
private $quantity;
Models model:
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #ORM\ManyToOne(targetEntity="Categories")
* #ORM\JoinColumn(name="category_id", referencedColumnName="id")
*/
private $category;
/**
* #var string
*
* #ORM\Column(name="name", type="string", length=255)
*/
private $name;
/**
* #var string
*
* #ORM\Column(name="url", type="string", length=255)
*/
private $url;
/**
* #var string
*
* #ORM\Column(name="image", type="string", length=255)
*/
private $image;
Categories Model:
/**
* #var int
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
private $id;
/**
* #var string
*
* #ORM\Column(name="title", type="string", length=50)
*/
private $title;
/**
* #var string
*
* #ORM\Column(name="url", type="string", length=255)
*/
private $url;
/**
* #var string
*
* #ORM\Column(name="description", type="string", length=140)
*/
private $description;
/**
* #var string
*
* #ORM\Column(name="image", type="string", length=100)
*/
private $image;
/**
* #var bool
*
* #ORM\Column(name="is_active", type="boolean")
*/
private $isActive;
/**
* created Time/Date
*
* #var \DateTime
*
* #ORM\Column(name="created_at", type="datetime", nullable=false)
*/
protected $createdAt;
/**
* updated Time/Date
*
* #var \DateTime
*
* #ORM\Column(name="updated_at", type="datetime", nullable=false)
*/
protected $updatedAt;

Answer 1

One Join is not necessary. You are joining the category table just for filter the id, but you can do that with IDENTITY, which is really helpful to reference the FK column. Your query should be faster like this:
public function findByCategory($category)
{
$qb = $this->createQueryBuilder('p');
$qb->select('p');
$qb->leftJoin('p.details', 'd');
$qb->leftJoin('p.model', 'm');
// $qb->leftJoin('m.category', 'c'); // this don't go anymore
$qb->where('IDENTITY(m.category) = :category');
$qb->andWhere('d.quantity > 0');
$qb->setParameter('category', $category);
$qb->addOrderBy('p.id', 'DESC');
$qb->setMaxResults(10);
return $qb->getQuery()->useQueryCache(true)->useResultCache(true, 31536000, uniqid())->getResult();
}