Magento 1.9 Performance – Difference Between Load and Using Collections

magento-1.9performance

Is there any difference in performance between load and the use of collections?

I was told that it is better to use this:

$product = Mage::getResourceModel('catalog/product_collection')->addAttributeToSelect('*')
            ->addAttributeToFilter('entity_id', $productId)
            ->getFirstItem();

instead of this:

$product = Mage::getModel('catalog/product')->load($item->getId());

Best Answer

Well, the real question here is "what's the difference between load and using collections ?"

Using collections is a huge performance boost for the following reasons, especially for EAV entities:

Loading an entity attribute value (EAV) model requires several heavy queries to execute. As the number of executed queries is multiplied with the number of products, we get extremely inefficient and slow code.

When you use the load method you load every single attributes assigned to the entity.

Let's say you only need to know the value of one attribute of your entity, loading is definitely not the right way to go and should use some code like this:

$product = Mage::getResourceModel('catalog/product_collection')->addAttributeToSelect('my_attribute') ->addAttributeToFilter('entity_id', $productId) ->getFirstItem();

Worst case scenario is when you use the load method in a loop, it can result in a disaster in terms of performances:

I suggest you have a look at the following official guide: http://info2.magento.com/rs/magentosoftware/images/Conquer_the_5_Most_Common_Magento_Coding_Issues_to_Optimize_Your_Site_for_Performance.pdf

Product Collection from Category

// Step 1
$category = Mage::getModel('catalog/category')->load($category_id);

// Step 2
$productCollection = Mage::getModel('catalog/product')->getCollection();

// Step 3
$productCollection->addCategoryFilter($category);

// Step 4
$productCollection
    ->addAttributeToSelect('sku')
    ->addAttributeToSelect('another_attribute')
    ->addAttributeToFilter('type_id', 'simple')
    ->addAttributeToFilter('status', 1);

// Now you can loop through your collection
foreach($productCollection as $product) {
    $product->getSku();
    $product->getAnotherAttribute();
    // and so on...
}

So what's going on?

We loaded a category model. We will use that in the product collection.
We instantiated the product collection model.
We added the category for filtering.
We added the appropriate attributes for selection and filtering.

NOTE: Do not use the asterisk unless you plan on using every attribute being returned. Just like you shouldn't use the asterisk in a MySQL query unless you plan on getting everything from that table.

Once I have all my attributes and filters in place, I can loop through my collection. I do not need to call the load() method because lazy loading does that for me.

Once I'm in the loop, I have access to the product object Mage_Catalog_Model_Product. I do not need to instantiate another model inside the loop. The collection does this for me.

Best Practices for Getting Resource/Collection Models in Magento 1.9

The methods Mage_Core_Model_Abstract::getResource() and Mage_Core_Model_Abstract::getCollection() are just handy shortcuts if you want to get the resource model or collection for an existing model instance.

They eventually call Mage::getResourceModel(), so if you don't already have an instantiated model, the more straightforward way to instantiate a collection or resource model is to use Mage::getResourceModel() directly. The result is always the same.

Best Answer

Related Solutions

Magento – Bad performance looping through all products

Product Collection from Category

So what's going on?

Best Practices for Getting Resource/Collection Models in Magento 1.9

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