Drupal Static and Extra caching

This article really does a great job teaching the concepts:
http://www.lullabot.com/blog/article/beginners-guide-caching-data-drupal-7
https://api.drupal.org/api/drupal/includes!bootstrap.inc/function/drupal...

The code snippet excerpts

To cache for just a page load. So repeated calls tot he same function that would return the same results are faster.

<?php
function my_module_function() {
 
$this_function_returns = &drupal_static(__FUNCTION__);
  if (!isset(
$this_function_returns)) {
   
// Do heavy lifting here, and populate $this_function_returns
   
$this_function_returns = ????
  }
  return
$this_function_returns;
}
?>

Database caching to make the heavy lifting last longer

<?php
function my_module_function() {
 
$this_function_returns = &drupal_static(__FUNCTION__);
  if (!isset(
$this_function_returns)) {
    if (
$cache = cache_get('UNIQUE_CACHE_ID')) {
     
$this_function_returns = $cache->data;
    }
    else {
     
// Do heavy lifting and populate $this_function_returns
     
$this_function_returns = ???
     
cache_set('UNIQUE_CACHE_ID', $this_function_returns, 'cache');
    }
  }
  return
$this_function_returns;
}
?>