Implements CacheArray::resolveCacheMiss().
Overrides CacheArray::resolveCacheMiss
protected function resolveCacheMiss($offset) {
$complete_schema = drupal_get_complete_schema();
$value = isset($complete_schema[$offset]) ? $complete_schema[$offset] : NULL;
$this->storage[$offset] = $value;
$this
->persist($offset);
return $value;
}