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 ('17', '32', '29', '12', '22', '26', '13') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('17', '32', '29', '12', '22', '26', '13') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=690581.33..690581.34 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52888.75..52888.76 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6642.54..51934.99 rows=381503 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{17,32,29,12,22,26,13}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6547.16 rows=381503 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{17,32,29,12,22,26,13}'::text[])) -> HashAggregate (cost=637692.50..637692.55 rows=3 width=20) -> Hash Anti Join (cost=593677.85..637246.64 rows=59449 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2908.85..41861.59 rows=139990 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{17,32,29,12,22,26,13}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2873.86 rows=139990 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{17,32,29,12,22,26,13}'::text[])) AND (c_acctbal > $0)) -> Hash (cost=403269.00..403269.00 rows=15000000 width=4) -> Seq Scan on orders (cost=0.00..403269.00 rows=15000000 width=4) (17 rows) COMMIT; COMMIT