QUERY PLAN
Aggregate (cost=54.24..54.25 rows=1 width=8)
-> Sort (cost=54.18..54.19 rows=4 width=228)
Sort Key: s.status, s.target_completed_at, s.updated_at DESC
-> Group (cost=54.11..54.14 rows=4 width=228)
Group Key: s.id, u.id
-> Sort (cost=54.11..54.12 rows=4 width=26)
Sort Key: s.id
-> Nested Loop (cost=0.14..54.07 rows=4 width=26)
-> Index Scan using tbl_users_pkey on tbl_users u (cost=0.14..8.16 rows=1 width=4)
Index Cond: (id = 5087)
Filter: (department_id = 1)
-> Seq Scan on tbl_tasks s (cost=0.00..45.86 rows=4 width=34)
Filter: ((parent_id IS NULL) AND (head_of = 5087))