Check the devel list, you'll see a drupal_get_path being issued. It's done by theme_tablesort_indicator(), which in turn calls theme_image(), which calls url(). Somehow, I'd like to get in and add "'alias' => TRUE" to prevent the path query.

These useless drupal_get_path calls are all over core. They may be quick, but they do take time.

Nancy

Injustice anywhere is a threat to justice everywhere. -- Dr. Martin L. King, Jr.

From: Earl Miles <merlin@logrus.com>
To: development@drupal.org
Sent: Tue, December 28, 2010 1:48:57 PM
Subject: Re: [development] URL Alias for Tablesort_sql

On 12/28/2010 6:53 AM, nan wich wrote:
> Before I go and submit a small performance patch to core, I am curious
> as to whether anyone, at any time, for any reason, has ever used a URL
> alias for the up and down images ('misc/arrow-asc.png',
> 'misc/arrow-desc.png')?

I'm pretty sure you can't use a URL alias for those, since they're
served directly by the webserver and not by Drupal.