QUERY PLAN
Aggregate (cost=79.11..79.12 rows=1 width=8)
-> Sort (cost=74.81..75.52 rows=287 width=228)
Sort Key: s.status, s.target_completed_at, s.updated_at DESC
-> HashAggregate (cost=60.22..63.09 rows=287 width=228)
Group Key: s.id, u.id
-> Nested Loop (cost=0.14..58.78 rows=287 width=26)
-> Index Scan using tbl_users_pkey on tbl_users u (cost=0.14..8.16 rows=1 width=4)
Index Cond: (id = 1000)
Filter: (department_id = 10)
-> Seq Scan on tbl_tasks s (cost=0.00..47.75 rows=287 width=34)
Filter: ((parent_id IS NULL) AND (head_of = 1000))