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 ('16', '24', '29', '34', '14', '23', '10') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('16', '24', '29', '34', '14', '23', '10') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691287.77..691287.78 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52951.81..52951.82 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6674.84..51995.38 rows=382573 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{16,24,29,34,14,23,10}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6579.19 rows=382573 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{16,24,29,34,14,23,10}'::text[])) -> HashAggregate (cost=638335.88..638335.93 rows=3 width=20) -> Hash Anti Join (cost=594299.44..637889.12 rows=59569 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2940.30..41902.01 rows=140332 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{16,24,29,34,14,23,10}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2905.22 rows=140332 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{16,24,29,34,14,23,10}'::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