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 ('33', '10', '19', '26', '27', '31', '16') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('33', '10', '19', '26', '27', '31', '16') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691163.97..691163.98 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52878.95..52878.96 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6640.47..51925.87 rows=381234 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,10,19,26,27,31,16}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6545.17 rows=381234 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{33,10,19,26,27,31,16}'::text[])) -> HashAggregate (cost=638284.94..638284.98 rows=3 width=20) -> Hash Anti Join (cost=594266.42..637845.16 rows=58637 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2907.28..41856.02 rows=139838 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,10,19,26,27,31,16}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2872.32 rows=139838 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,10,19,26,27,31,16}'::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