QUERY PLAN
Aggregate (cost=60.17..60.18 rows=1 width=8)
-> Sort (cost=60.02..60.04 rows=10 width=228)
Sort Key: s.created_at DESC
-> Group (cost=59.78..59.85 rows=10 width=228)
Group Key: s.id, u.id
-> Sort (cost=59.78..59.80 rows=10 width=16)
Sort Key: s.id
-> Nested Loop (cost=0.00..59.61 rows=10 width=16)
-> Seq Scan on tbl_users u (cost=0.00..8.16 rows=1 width=4)
Filter: ((id = 1000) AND (department_id = 10))
-> Seq Scan on tbl_tasks s (cost=0.00..51.35 rows=10 width=24)
Filter: ((parent_id IS NULL) AND (head_of = 1000) AND (status = '0'::smallint))