QUERY PLAN
Aggregate (cost=100.73..100.75 rows=1 width=8)
-> Group (cost=100.72..100.72 rows=1 width=224)
Group Key: s.id
InitPlan 1 (returns $0)
-> Aggregate (cost=48.89..48.90 rows=1 width=32)
-> Seq Scan on tbl_tasks s_1 (cost=0.00..48.84 rows=20 width=13)
Filter: ((tree_path IS NOT NULL) AND (head_of = 1001) AND (status = '1'::smallint))
-> Sort (cost=51.82..51.82 rows=1 width=4)
Sort Key: s.id
-> Seq Scan on tbl_tasks s (cost=0.00..51.81 rows=1 width=4)
Filter: ((tree_path @> $0) AND (head_of = 1001) AND (status = '1'::smallint))