How does one reduce the number of stored revisions?

Question

How does one reduce the number of stored revision (e.g. 5 max) for post types that support revisions?

Answer 1

add to your wp-config.php file the following line:

// set max post revisions    
define('WP_POST_REVISIONS', 5);

source: http://codex.wordpress.org/Editing_wp-config.php#Post_Revisions

Answer 2

Just use the plugin. Simpler than screwing around with it, and provides more control.

http://wordpress.org/extend/plugins/revision-control/

Answer 3

@Piet's answer is the best, but some sql code to remove all old revisions older than 28 days:

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'
AND a.post_date < DATE_ADD(NOW(), INTERVAL -28 DAY);

SQL and PHP code (for diffrent WP_PREFIX than "wp_") iworks_revisions.zip

Answer 4

I'm not sure of an automatic way but there is always running the MySQL Query DELETE FROM wp_posts WHERE post_type = "revision" (source) I haven't done it but I'm sure it works. I'd look for a plugin by now there has to be something.