QUERY PLAN
Limit (cost=303.04..303.05 rows=1 width=236)
InitPlan 1 (returns $0)
-> Aggregate (cost=150.01..150.02 rows=1 width=32)
-> Seq Scan on tbl_tasks s_1 (cost=0.00..150.00 rows=2 width=13)
Filter: ((tree_path IS NOT NULL) AND (head_of = 1001) AND (status = '0'::smallint))
-> Sort (cost=153.03..153.03 rows=1 width=236)
Sort Key: s.created_at DESC
-> Group (cost=153.01..153.02 rows=1 width=236)
Group Key: s.id
-> Sort (cost=153.01..153.01 rows=1 width=236)
Sort Key: s.id
-> Seq Scan on tbl_tasks s (cost=0.00..153.00 rows=1 width=236)
Filter: ((parent_id IS NULL) AND (tree_path @> $0) AND (head_of = 1001) AND (status = '0'::smallint))