QUERY PLAN
Limit (cost=53.49..53.52 rows=8 width=204)
-> Sort (cost=53.49..53.52 rows=8 width=204)
Sort Key: s.target_completed_at, s.updated_at DESC
-> Group (cost=53.31..53.38 rows=8 width=204)
Group Key: s.id, u.id
-> Sort (cost=53.31..53.34 rows=8 width=204)
Sort Key: s.id, u.id
-> Nested Loop Left Join (cost=0.14..53.20 rows=8 width=204)
Join Filter: (u.id = s.head_of)
-> Seq Scan on tbl_tasks s (cost=0.00..48.91 rows=8 width=200)
Filter: ((parent_id IS NULL) AND (head_of = 1000) AND (status = '0'::smallint))
-> Materialize (cost=0.14..4.17 rows=1 width=4)
-> Index Only Scan using tbl_users_pkey on tbl_users u (cost=0.14..4.16 rows=1 width=4)
Index Cond: (id = 1000)