A new feature that was shipped with WordPress 2.6 and later is the ability to create tracking revisions for each post. This is particularly handy if there are many authors that write on the same WordPress blog. Post revisions is intended to keep previous versions of a post after it have been modified. It helps track changes to blog post in case there is a need to revert back to an earlier version. Each time a post has been saved, a Post Revision is created. Those happens even if the same author is hitting the “Update Post” button.

There is also the AutoSave option which automatically save the content of the post at an interval, just in case the WordPress admin page is closed accidentally or Internet connection is lost before you had a chance to save your work.

There are downsides to post revisions, especially if you are the only author of your blog:

MySQL database grows unnecessarily

Let’s say you just started a new blog a few weeks back and you managed to create 20 posts. If those 20 posts got edited or changed 5 times each, you will technically have around 100 posts stored in the database. That’s a lot of posts that you don’t have. This caused the size of WordPress database to grow and use up space unnecessarily.

Slow Database performance

MySQL is a pretty solid and robust database, but bloating it with unnecessary content, such as post revisions, can have a detrimental performance impact on your WordPress blog, especially in the long run. In other words, you may notice a delay when saving new posts, loading your blog or making other changes that involved WordPress database.

In order to turn off and disable Post Revisions in WordPress, add the following line to your wp-config.php:

define (’WP_POST_REVISIONS’, false);

wp-config.php can found on the root directory of your WordPress installation folder. If your WordPress is self-hosted and you are using cPanel Control Panel, go to File Manager, then click WWW folder icon. You should be able to locate the folder of your WordPress and click the right folder icon. With cPanel, you can edit wp-config.php by clicking the file from the list and Edit File from the top right hand side. This saves you downloading (if you don’t have a copy), changing and then uploading wp-config.php.

Once wp-config.php is saved with the line above, WordPress will no longer save post revisions in the MySQL database, except AutoSave ones, which are not saved after you done saving the post.