This functionality will search for potential missing indexes in your Moodle server, generating (but not executing!) automatically the needed SQL statements to keep everything updated.

Once generated you can copy such statements and execute them safely with your favourite SQL interface (don't forget to backup your data before doing that).

It's highly recommended to be running the latest (+ version) available of your Moodle release before executing the search of missing indexes.

This functionality doesn't perform any action against the DB (just reads from it), so can be safely executed at any moment.