ajax and view

If i want to update a portion of the view with an ajax request i have always to create a partial view with that portion?

You may take it from cache as well.

How?

http://www.yiiframework.com/doc/guide/1.1/en/caching.overview

http://dev.mysql.com/doc/refman/5.1/en/query-cache.html

http://davidwalsh.name/cache-ajax

http://api.jquery.com/jQuery.ajax/