Now you can easily control the revisions for each stored post type (posts, pages and other custom post types) in your WordPress installation. This way you can reduce the weight of your site’s database and get noticeable performance from faster database queries.
WP Revisions Control is the new WordPress plugin. Install and activate it, upon activation the plugin adds a new section (WP Revisions Control) in your Dashboard -> Settings -> Writing admin page. Now all you have to do is enter the number of revisions to save for each post type listed. For retaining all revisions for a given post type simply leave that field empty.