QUERY PLAN
Limit (cost=104.93..104.94 rows=1 width=191)
InitPlan 1 (returns $0)
-> Aggregate (cost=50.88..50.89 rows=1 width=32)
-> Seq Scan on tbl_tasks s_1 (cost=0.00..50.87 rows=2 width=13)
Filter: ((tree_path IS NOT NULL) AND (head_of = 1001) AND (status = '0'::smallint))
-> Sort (cost=54.04..54.05 rows=1 width=191)
Sort Key: s.end_at, s.created_at DESC
-> Group (cost=54.02..54.03 rows=1 width=191)
Group Key: s.id
-> Sort (cost=54.02..54.03 rows=1 width=191)
Sort Key: s.id
-> Seq Scan on tbl_tasks s (cost=0.00..54.02 rows=1 width=191)
Filter: ((parent_id IS NULL) AND (tree_path @> $0) AND (head_of = 1001) AND (status = '0'::smallint))