Hello,
I tried to use the code provided in the FAQ, changing 30 to 5 so that it would purge stats before September but something went wrong and stats before today got purged literally. This is the code I used:
DELETE piwik_log_visit, piwik_log_link_visit_action
FROM piwik_log_visit INNER JOIN piwik_log_link_visit_action
WHERE piwik_log_visit.idvisit = piwik_log_link_visit_action.idvisit
AND visit_server_date <= CURRENT_DATE() - 5
Kind Regards,
A.J. Angel