Handling WordPress Post Revisions the right way

I have came across so many blogs which talk about disabling WordPress Post revisions to have some performance gain but almost each of them gives the solution which is not correct, at least not completely.

Deleting WordPress Post Revisions

They just tell the users to execute the following MySQL command but its not the correct way of doing so.

DELETE FROM wp_posts WHERE post_type = "revision";

It will leave some data related to revisions in the database. The correct method of removing the post revisions is to run this command

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';

Even the above method leave some traces behind, Mike Schinkel explains in comments how post revisions can be removed by creating a custom PHP file in which we loads WordPress and run a loop deleting every revision. Here is the code :

<?php
require_once('wp-load.php');

$posts = get_posts('post_type=revision&post_status=any&numberposts=-1');
foreach($posts as $post)
{
echo "{$post->post_title}\n";
wp_delete_post($post->ID,true);
}
?>

Create a php file with the above code and load it to WordPress root and then open in browser. It will delete all the post revisions and will output their titles too. Thanks Mike Schinkel!

Disable WordPress Post Revisions

You can disable them by adding the following line in your wp-config.php file (located in WordPress root)

define('WP_POST_REVISIONS', false);

Limit WordPress Post Revisions Count

You can also limit the number of post revisions count to 3 or 5 by adding the following line in your wp-config.php file (located in WordPress root)

define('WP_POST_REVISIONS', 5);

Just change the value as per your needs.

Advantages of disabling & removing Post Revisions

Post Revisions are created for changes you make to the post. You may not (in fact many of us) don’t need to keep them and it also increases our database size. Disabling them takes care that post revisions are not created and removing them is a a good option to lighten your database size. Remember, smaller database means there is less stuff to look for which means faster speed.

Thanks to Sitepoint for the correct code. If you like any kind of help with WordPress then let me know, I would love to help you 🙂