If you spend a lot of time revising a page or a post, you can build up quite a number of revisions in the database.
The following line in the wp-config.php file in the root of the site will limit the number of revisions saved to 5. You can use whatever number you want, within reason.
define('WP_POST_REVISIONS', 5); |
Other tricks using the wp-config.php file can be found at http://digwp.com/2009/06/wordpress-configuration-tricks/.