Today I have to admit I did not open IDE somehow for more than just one line of code 😀 Got stuck into analyzing the logs and cleaning one of my website’s database.
All in One SEO plugin (do not recommend!) created around 3 million garbage entries into the WP+WooCommerce database with scheduled actions (mainly by aioseo_sitemap_ping). It is multiple times more than the whole site itself.
For example:
wp_actionscheduler_logstable had 1 973 366 entrieswp_actionscheduler_actionstable had 912 058 entries
I emphasize that these entries are just unwanted garbage and do not create any value. In order to clear it you need to enter the database (through PMA or some other way) and run DELETE FROM table WHERE ...; SQL query. I can assure that deleting millions of entries takes some time from database engine 🙂
The only line I wrote today (except SQL queries) was add_filter( 'aioseo_sitemap_ping', '__return_false' ); to kill the unnecessary scheduled action.