Old post revisions are perfectly harmless, and you don’t need to delete them in most cases. However, if you have a very large website with thousands of articles, then deleting old post revisions can help you reduce backup sizes.
First, you’ll need to install and activate the WP-Optimize plugin.
Upon activation, go to WP-Optimize » Database page and check the box next to ‘Clean all post revisions’ option.
Now click on the ‘Run optimization’ button to delete all post revisions. You can uninstall the plugin after you have deleted the revisions.
Once you have cleaned up revisions, feel free to uninstall and delete the plugin.
Deleting WordPress post revisions via phpMyAdmin
Advanced users can also delete WordPress posts revisions via phpMyAdmin.
First, make sure that you have created a complete WordPress database backup.
After that, simply login to your WordPress hosting control panel and click on the phpMyAdmin icon.
Next, you need to select your WordPress database from the left column. PhpMyAdmin will now display tables in your WordPress database.
After that, you need to click on the SQL tab from the top menu.
This will load phpMyAdmin’s SQL interface. From here you can manually run commands on your WordPress database.
You need to enter the following code.
Tables can't be imported directly. Please insert an image of your table which can be found here.
Don’t forget to replace wp_ with your own WordPress database prefix. After that, click on the Go button to run the command.
PhpMyAdmin will now delete all revisions from your WordPress database.
Note: Deleting revisions will not stop WordPress from saving revisions for your future posts.