QUERY PLAN
Limit (cost=297.17..297.18 rows=1 width=236)
InitPlan 1 (returns $0)
-> Aggregate (cost=147.14..147.15 rows=1 width=32)
-> Seq Scan on tbl_tasks s_1 (cost=0.00..147.00 rows=54 width=13)
Filter: ((tree_path IS NOT NULL) AND (head_of = 1001))
-> Sort (cost=150.03..150.03 rows=1 width=236)
Sort Key: s.created_at DESC
-> Group (cost=150.01..150.02 rows=1 width=236)
Group Key: s.id
-> Sort (cost=150.01..150.01 rows=1 width=236)
Sort Key: s.id
-> Seq Scan on tbl_tasks s (cost=0.00..150.00 rows=1 width=236)
Filter: ((parent_id IS NULL) AND (tree_path @> $0) AND (head_of = 1001))