Unique  (cost=50607.57..51621.47 rows=7700 width=32)
  ->  Gather Merge  (cost=50607.57..51544.47 rows=7700 width=32)
        Workers Planned: 2
        ->  Unique  (cost=49607.55..49655.68 rows=3850 width=32)
              ->  Sort  (cost=49607.55..49617.18 rows=3850 width=32)
                    Sort Key: c.id, cr.id, ra.userid, mc.timemodified
                    ->  Parallel Hash Right Join  (cost=41485.21..49378.27 rows=3850 width=32)
                          Hash Cond: ((cc.criteriaid = cr.id) AND (cc.userid = ra.userid))
                          ->  Parallel Seq Scan on mdl_course_completion_crit_compl cc  (cost=0.00..6316.57 rows=210157 width=16)
                          ->  Parallel Hash  (cost=41427.46..41427.46 rows=3850 width=32)
                                ->  Hash Join  (cost=11477.83..41427.46 rows=3850 width=32)
                                      Hash Cond: (cr.moduleinstance = cm.id)
                                      ->  Parallel Hash Join  (cost=11282.58..41221.50 rows=4078 width=48)
                                            Hash Cond: ((cr.moduleinstance = mc.coursemoduleid) AND (ra.userid = mc.userid))
                                            ->  Hash Join  (cost=518.54..25224.46 rows=211236 width=32)
                                                  Hash Cond: (ra.contextid = con.id)
                                                  ->  Parallel Seq Scan on mdl_role_assignments ra  (cost=0.00..20763.14 rows=488114 width=16)
                                                  ->  Hash  (cost=448.79..448.79 rows=5580 width=32)
                                                        ->  Hash Join  (cost=292.54..448.79 rows=5580 width=32)
                                                              Hash Cond: (cr.course = c.id)
                                                              ->  Seq Scan on mdl_course_completion_criteria cr  (cost=0.00..84.48 rows=4248 width=24)
                                                              ->  Hash  (cost=273.36..273.36 rows=1534 width=24)
                                                                    ->  Merge Join  (cost=0.63..273.36 rows=1534 width=24)
                                                                          Merge Cond: (c.id = con.instanceid)
                                                                          ->  Index Only Scan using mdl_cour_id_pk on mdl_course c  (cost=0.28..101.78 rows=1167 width=8)
                                                                          ->  Index Scan using mdl_cont_ins_ix on mdl_context con  (cost=0.29..885.41 rows=12894 width=16)
                                            ->  Parallel Hash  (cost=6365.42..6365.42 rows=210842 width=24)
                                                  ->  Parallel Seq Scan on mdl_course_modules_completion mc  (cost=0.00..6365.42 rows=210842 width=24)
                                      ->  Hash  (cost=139.00..139.00 rows=4500 width=8)
                                            ->  Seq Scan on mdl_course_modules cm  (cost=0.00..139.00 rows=4500 width=8)