Drupal - Can we get full count of results from a query that is extended by PagerDefault

With the existing pager class I don't think you can get that data without running the count query again. The total count is queried directly and saved to a local var before being passed off to pager_default_initialize()...it's not saved anywhere.

One option would be to extend the default class and use that for your pager queries. This is un-tested but I think it'll do the trick

class MyPager extends PagerDefault {

  /**
   * Overrides PagerDefault::execute().
   */
  public function execute() {
    // Add convenience tag to mark that this is an extended query. We have to
    // do this in the constructor to ensure that it is set before preExecute()
    // gets called.
    if (!$this->preExecute($this)) {
      return NULL;
    }

    // A NULL limit is the "kill switch" for pager queries.
    if (empty($this->limit)) {
      return;
    }
    $this->ensureElement();

    // Get the total items from our new statically cached function.
    $total_items = $this->getTotalItemCount();

    $current_page = pager_default_initialize($total_items, $this->limit, $this->element);
    $this->range($current_page * $this->limit, $this->limit);

    // Now that we've added our pager-based range instructions, run the query normally.
    return $this->query->execute();
  }

  /**
   * Cache the results of PagerDefault::getCountQuery().
   */
  public function getTotalItemCount() {
    static $total_items = NULL;

    if ($total_items === NULL) {
      $total_items = $this->getCountQuery()->execute()->fetchField();
    }

    return $total_items;
  }

}

You could then construct a query like the following

$query = db_select('table', 't')
  ->fields('t')
  ->condition('foo', 'bar')
  ->extend('MyPager');

$current_items = $query->execute();
$total_items = $query->getTotalItemCount();

There might be an easier way, but I just can't see it.