Your WordPress Database holds the information of all your posts, pages, images, and settings. It also has copies of all those revisions you created, or that were automatically made for you.
- This site has around 1500 entries in the posts database. Nearly 500 are revisions, which may not be redundant as the posts are published.
- There were also out of date transient entries. These are records made by plugins and WordPress to remind of issues or situations and that have a theoretical lifespan. But they don’t always get deleted after they have expired.
- Plugins can save settings in your database. If you remove a plugin, they don’t all take the time to remove all their database entries.
- If you run a shopping cart, then you could have lots of abandoned cart data, which may be of no useful purpose to you.
You can argue whether such database cleaning makes your site run faster. it is unlikely to make big in most cases. However, the file size of the database will make a difference when doing backups.
Some larger transaction sites, like shopping cart site, have seen reductions of 40% plus.
If you never tried to optimize your database tables, you would never have checked that they are not corrupted?
So for all these reasons, I suggest you at least run the plugin to get its summary of your site’s situation. If changes are to be done, then the cautious of use will say take a backup first, and the ultra-cautious would say; take a backup of your site, install on a test site/server and then run the optimize on that.
You can see me running WP-Optimize on this site’s data below.