Invalidating Archives/Reimporting

I was reading through How to - Analytics Platform - Matomo and was wondering, if I have multiple sites in my piwik, but only want to reprocess logs for a certain site, should I be deleting the archive_* tables, or just deleting the entries inside of the tables for that particular site? I am eventually thinking that I might allow individual users to trigger a reimport for their site for specific days, and I don’t want to impact other sites by removing their archives (even if they would be repopulated).

Also, per How to - Analytics Platform - Matomo, is issuing a command to the API to invalidate archives necessary or optional?

Of course, you may only delete the archive entries for particular websites if you only want these websites to be re-processed. Enjoy