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', '24', '32', '22', '27', '34', '25') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('14', '24', '32', '22', '27', '34', '25') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=691078.82..691078.83 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52841.62..52841.63 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6632.55..51891.09 rows=380211 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,24,32,22,27,34,25}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6537.50 rows=380211 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{14,24,32,22,27,34,25}'::text[])) -> HashAggregate (cost=638237.12..638237.17 rows=3 width=20) -> Hash Anti Join (cost=594261.75..637792.49 rows=59285 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2902.61..41839.52 rows=139387 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,24,32,22,27,34,25}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2867.77 rows=139387 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{14,24,32,22,27,34,25}'::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