SELECT vl.plugin_key AS repository_type, COUNT(vl.plugin_key) AS plans_sum
  FROM plan_vcs_location AS pvl 
  JOIN vcs_location      AS vl ON pvl.vcs_location_id = vl.vcs_location_id 
  JOIN build             AS b  ON b.build_id = pvl.plan_id
  JOIN project           AS p  ON b.project_id = p.project_id
GROUP BY repository_type
ORDER BY total_of_plans DESC;