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 ('32', '12', '14', '34', '26', '16', '30') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('32', '12', '14', '34', '26', '16', '30') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------ Sort (cost=690512.43..690512.43 rows=3 width=20) Sort Key: (substr((public.customer.c_phone)::text, 1, 2)) InitPlan 1 (returns $0) -> Aggregate (cost=52859.59..52859.60 rows=1 width=4) -> Bitmap Heap Scan on customer (cost=6636.35..51907.83 rows=380704 width=4) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,12,14,34,26,16,30}'::text[])) AND (c_acctbal > 0::double precision)) -> Bitmap Index Scan on customer_c_phone_idx_c_acctbal (cost=0.00..6541.18 rows=380704 width=0) Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{32,12,14,34,26,16,30}'::text[])) -> HashAggregate (cost=637652.75..637652.80 rows=3 width=20) -> Hash Anti Join (cost=594262.90..637214.26 rows=58466 width=20) Hash Cond: (public.customer.c_custkey = orders.o_custkey) -> Bitmap Heap Scan on customer (cost=2903.76..41843.50 rows=139495 width=24) Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,12,14,34,26,16,30}'::text[])) AND (c_acctbal > $0)) -> Bitmap Index Scan on customer_c_phone_idx (cost=0.00..2868.89 rows=139495 width=0) Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{32,12,14,34,26,16,30}'::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