- Backup your DB
- Get access to the DB on any mysql client
- To full RESET Delete all these tables:
- piwik_archive_blob_2014_03
- piwik_archive_blob_2014_04 (year and month of data)
- piwik_archive_numeric_2014_03
- piwik_archive_numeric_2014_04 (year and month of data)
for a partially delete, drop only the older data.
- Delete all the records on this table (or keep the latest)
- piwik_log_link_visit_action
YOU HAVE RESET IT!