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 ('24', '23', '32', '16', '21', '14', '17') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('24', '23', '32', '16', '21', '14', '17') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=690606.26..690606.27 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52915.24..52915.25 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6648.18..51959.66 rows=382228 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,23,32,16,21,14,17}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6552.62 rows=382228 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{24,23,32,16,21,14,17}'::text[])) -> HashAggregate (cost=637690.95..637690.99 rows=3 width=20) -> Hash Anti Join (cost=594268.64..637250.71 rows=58699 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2909.50..41863.89 rows=140053 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,23,32,16,21,14,17}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2874.49 rows=140053 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,23,32,16,21,14,17}'::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