One thing I have spent a lot of time on recently is cleaning up orphaned tables in WordPress from running blogs for 5+ years where I do a ton of plugin testing. I have installed probably 200+ plugins for various review/testing purposes over the past years and many of them do not properly clean up SQL database tables when you simply uninstall them, they leave these orphaned tables often with bloated rows and data that just aren’t needed anymore.
So for anyone unfamiliar with WordPress, here are the default WordPress tables.
This means when you are looking at your WordPress database with PHPMyAdmin or another SQL browser and you see other tables that aren’t listed, they are plugin related tables. It isn’t always easy to match the table with which plugin, though some use pre-fixes that give you an idea, it isn’t always so easy to point it out. In this case it may require you to do some digging, to figure it out or simply backup your database, drop the table and see if a plugin functionality is lost.
In the above, I am truncating my prefix for security reasons, but after the prefix you can see the 1st plugin is for EasyAzon and is a table for holding IP lookup information. The Flicker_post could be some flickr related plugin or something that stores flickr information, but I never had a plugin that had Flickr in the name directly so most likely this would be one that searches for images for posts. The frm tables are for Formidable Pro, but you wouldn’t know that just by seeing frm acronym.
I found the dmsguestbook table, which I haven’t used this plugin in 3 years, yet the table was still out there orphaned.
So if you find that you have been using a lot of plugins over the past few years or you have uninstalled plugins recently you may want to go into your PHPMyAdmin and make sure you drop and clean up those tables for plugins that you know you will never install or need again.
In the PHPMyAdmin you would click on the table, click on Operations and then click Delete the Table.
But again, serious caution is needed here, make sure you do a full database backup first and double check on the next screen to confirm you are actually selecting the table that you want to drop.
If you make a mistake and drop one of the core WordPress tables you could lose important blog data or corrupt your WordPress install terribly, so make sure you have comfort and familiarity with the tables before performing a cleanup operation like this.
If you have any questions related to removing WordPress tables, cleanup of WordPress database just let me know.