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 ('14', '10', '29', '13', '21', '31', '15') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('14', '10', '29', '13', '21', '31', '15') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691176.33..691176.34 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52886.11..52886.12 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6641.99..51932.53 rows=381430 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,10,29,13,21,31,15}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6546.64 rows=381430 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{14,10,29,13,21,31,15}'::text[])) -> HashAggregate (cost=638290.14..638290.19 rows=3 width=20) -> Hash Anti Join (cost=594267.13..637850.13 rows=58668 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2907.99..41858.63 rows=139910 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,10,29,13,21,31,15}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2873.02 rows=139910 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,10,29,13,21,31,15}'::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