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 ('32', '23', '19', '29', '34', '25', '22') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('32', '23', '19', '29', '34', '25', '22') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691166.50..691166.51 rows=3 width=20) Sort Key: (substr((customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52925.84..52925.85 rows=1 width=4) -> Bitmap Heap Scan on customer customer_1 (cost=6651.28..51969.61 rows=382489 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,23,19,29,34,25,22}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6555.66 rows=382489 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{32,23,19,29,34,25,22}'::text[])) -> HashAggregate (cost=638240.58..638240.62 rows=3 width=20) Group Key: substr((customer.c_phone)::text, 1, 2) -> Hash Anti Join (cost=594269.36..637794.39 rows=59492 width=20) Hash Cond: (customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2910.22..41863.69 rows=140018 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,23,19,29,34,25,22}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2875.21 rows=140018 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,23,19,29,34,25,22}'::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) Planning time: 2.220 ms (19 rows) COMMIT; COMMIT