How To Disable WordPress Post Revisions

Since WordPress 2.6, we have a post revisions each time we edit a post. This feature maybe useful if you have more than one blog author or if you really want to keep track of your post revisions. If you think this feature is annoying, you can turn it off by adding the following code in wp-config.php.

define('WP_POST_REVISIONS', false);

It will be better if you set this thing just after setting up your blog. If you add this code after you have several posts (that are creating post revisions), you can optionally delete those post revisions using this SQL query:

DELETE a,b,c
FROM wp_posts a
LEFT JOIN wp_term_relationships b ON (a.ID = b.object_id)
LEFT JOIN wp_postmeta c ON (a.ID = c.post_id)
WHERE a.post_type = 'revision'

Of you course you can run this query from phpMyAdmin or any MySQL database manager.

I think WordPress should add this option on their next release, instead of hard-coded in wp-config.php.