Hi,
unfortunately tables visited_urls, referer_urls and referers are strictly connected (i.e. each entry in the referers has a foreign key on an entry of the visited_urls, and another one on an entry of the referer_urls). So it is not possible to simply delete entries from the visited_urls tables being sure to not delete an item in use (pointed by referers).

A good solution could be to write a (sql) script to extract only the most recent entries from the referers (e.g. last month) in a new table, and to build the referred tables accordingly. At the end replace the new with the old ones.

But this is just my first idea, there is no automatic process to do this ATM.

Kind regards
Luigi

Unfortunately as I told before I do not have nothing to accomplish this.

Sorry

I will consider it, thank you.