What performance gain will this code give?

Question

Code sample # 1

$customer_obj = Mage::getModel('customer/customer');
foreach(){
$customer_data = $customer_obj->load(customer_id);
$customer_data->getFirstname();
$customer_data->getEmail();
........
}

Code sample # 2

$customer_obj = Mage::getModel('customer/customer');
foreach(){
$customer_obj->load(customer_id)->getFirstname();
$customer_obj->load(customer_id)->getEmail();
.........
}

The loop count will be something around 1800-2000 every day.It is one time cron job every day

I am assuming it in this way, in sample # 1 $customer_data will have the entire customer details in memory and from there on wards it will fetch it from memory.but in sample # 2 it always hit db with every load call

Can someone please enlighten me?

Answer 1

For your question:

code sample 1 is better, because it only does the load once for each customer. code sample 2 does multiple loads per customer.

But as Patrick Steenks mentions, it is even much better to use a customer collection to do this, because then you only have ONE query for ALL customers :)

Answer 2

I think it is better to use the collection method of magento, and then only load the attributes you need:

$collection = Mage::getModel("customer/customer")->getCollection()->addAttributeToSelect('firstname','email');

Then loop with a foreach through this collection.