BEGIN; BEGIN EXPLAIN select cntrycode, count(*) as numcust, sum(c_acctbal) as totacctbal from ( select substr(c_phone, 1, 2) as cntrycode, c_acctbal from customer where substr(c_phone, 1, 2) in ('15', '32', '23', '28', '11', '22', '29') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('15', '32', '23', '28', '11', '22', '29') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691124.93..691124.94 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52849.15..52849.16 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6634.13..51898.10 rows=380418 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{15,32,23,28,11,22,29}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6539.02 rows=380418 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{15,32,23,28,11,22,29}'::text[])) -> HashAggregate (cost=638275.70..638275.75 rows=3 width=20) -> Hash Anti Join (cost=594264.84..637837.15 rows=58474 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2905.70..41850.48 rows=139687 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{15,32,23,28,11,22,29}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2870.78 rows=139687 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{15,32,23,28,11,22,29}'::text[])) AND (c_acctbal > $0)) -> Hash (cost=403671.84..403671.84 rows=15014984 width=4) -> Seq Scan on orders (cost=0.00..403671.84 rows=15014984 width=4) (17 rows) COMMIT; COMMIT