When a blog-post is written using WordPress, its auto-saved after every 60 seconds. This is to prevent accidental loss due to system or browser crash. In fact, every blog-post has an auto-saved version if changes are made in it.
Additionally, when an author manually saves a post or make changes to it and publish, the previous (same) post is saved as revision.
On an average, a post has a minimum of 5-6 revisions, which are all stored in database consuming big space. A blog with 500 posts might be as heavy as 2500 posts. So a better idea is to free it. We can do this by executing simple MySql query on the database for a WordPress blog.
Stepwise Instructions to delete all revisions
1. First login to your webserver. Here we’ve CPanel as the interface.
2. Now go to ‘phpMyAdmin’.
3. Select your WordPress database. Here its named as ‘wordpress’, your database might be named differently.
4. Select ‘wp_posts’ table, then click SQL at the top. Enter the following query and execute it pressing ‘Go’ button. Click ‘Ok’ when asked for confirmation.
That’s all! All revisions should be deleted by now. This would free up lot of space from your MySQL database. You can also delete drafts and trash similarly.
[This process is useful in freeing up space, and making WordPress database to perform faster. Its completely safe.]