How do I update products without resetting attributes to default values

Question

I have a script that updates stock and price but it seems to save all attributes with a default value back to the default.

The collection is loaded like this:

$productsCollection = Mage::getModel('catalog/product')->getCollection()
            ->addAttributeToSelect(array('visibility','name','price','plu'))
            ->addAttributeToFilter('sku', array('in' => $this->skuArray));

foreach ($productsCollection as $product)
        { 
            //update stuff here
            $product->save();

        }

I have read somewhere that using load() is needed to save only those attributes specifically selected but if I do that I get a memory exhausted error.

Can someone give me some pointers on how to modify what I have in order to only save the attributes I have selected?

Answer 1

After some more investigation I solved it.

save() will save all attributes and because no value was given for those attributes with default values they were getting reset back to their default values.

Replacing $product->save() with $product->getResource()->saveAttribute($product, 'attribute_name') saves only those attributes and leaves all others untouched.

As an added bonus the script runs a lot quicker.