Will Apache load and process .htaccess file during every request

Question

... or there is an optimization which reduces operation cost to single stat() call in case file is unmodified?

Please provide a reference link of some kind.

Answer 1

Just read the docs yourself, it's listed in there:

Also, the .htaccess file is loaded every time a document is requested.

http://httpd.apache.org/docs/2.4/howto/htaccess.html