BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
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
				('22', '27', '30', '33', '29', '32', '14')
			and c_acctbal > (
				select
					avg(c_acctbal)
				from
					customer
				where
					c_acctbal > 0.00
					and substr(c_phone, 1, 2) in
						('22', '27', '30', '33', '29', '32', '14')
			)
			and not exists (
				select
					*
				from
					orders
				where
					o_custkey = c_custkey
			)
	) as vip
group by
	cntrycode
order by
	cntrycode;
                                                                              QUERY PLAN                                                                              
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=694187.55..694187.56 rows=3 width=20) (actual time=17444.076..17444.077 rows=7 loops=1)
   Sort Key: (substr((public.customer.c_phone)::text, 1, 2))
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=269188 read=57667 dirtied=253 written=15
   InitPlan 1 (returns $0)
     ->  Aggregate  (cost=52929.86..52929.87 rows=1 width=4) (actual time=1135.551..1135.551 rows=1 loops=1)
           Buffers: shared hit=25 read=36318
           ->  Bitmap Heap Scan on customer  (cost=6651.27..51973.28 rows=382629 width=4) (actual time=173.519..1020.813 rows=381554 loops=1)
                 Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{22,27,30,33,29,32,14}'::text[])) AND (c_acctbal > 0::double precision))
                 Buffers: shared hit=25 read=36318
                 ->  Bitmap Index Scan on customer_c_phone_idx_c_acctbal  (cost=0.00..6555.61 rows=382629 width=0) (actual time=153.912..153.912 rows=381554 loops=1)
                       Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{22,27,30,33,29,32,14}'::text[]))
                       Buffers: shared hit=8 read=1057
   ->  HashAggregate  (cost=641257.62..641257.66 rows=3 width=20) (actual time=17444.000..17444.003 rows=7 loops=1)
         Buffers: shared hit=269186 read=57667 dirtied=253 written=15
         ->  Hash Anti Join  (cost=597221.06..640814.13 rows=59132 width=20) (actual time=16590.867..17398.113 rows=63879 loops=1)
               Hash Cond: (public.customer.c_custkey = orders.o_custkey)
               Buffers: shared hit=269186 read=57667 dirtied=253 written=15
               ->  Bitmap Heap Scan on customer  (cost=2911.22..41870.05 rows=140222 width=24) (actual time=1243.239..1615.590 rows=190641 loops=1)
                     Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{22,27,30,33,29,32,14}'::text[])) AND (c_acctbal > $0))
                     Buffers: shared hit=35207 read=36856
                     ->  Bitmap Index Scan on customer_c_phone_idx  (cost=0.00..2876.17 rows=140222 width=0) (actual time=1229.877..1229.877 rows=190641 loops=1)
                           Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{22,27,30,33,29,32,14}'::text[])) AND (c_acctbal > $0))
                           Buffers: shared hit=36 read=36855
               ->  Hash  (cost=405686.04..405686.04 rows=15089904 width=4) (actual time=15334.292..15334.292 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 527872kB
                     Buffers: shared hit=233976 read=20811 dirtied=253 written=15
                     ->  Seq Scan on orders  (cost=0.00..405686.04 rows=15089904 width=4) (actual time=0.033..6838.568 rows=15015000 loops=1)
                           Buffers: shared hit=233976 read=20811 dirtied=253 written=15
 Total runtime: 17575.901 ms
(30 rows)

COMMIT;
COMMIT