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
				('33', '24', '31', '27', '22', '26', '32')
			and c_acctbal > (
				select
					avg(c_acctbal)
				from
					customer
				where
					c_acctbal > 0.00
					and substr(c_phone, 1, 2) in
						('33', '24', '31', '27', '22', '26', '32')
			)
			and not exists (
				select
					*
				from
					orders
				where
					o_custkey = c_custkey
			)
	) as vip
group by
	cntrycode
order by
	cntrycode;
                                                                              QUERY PLAN                                                                              
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=697144.63..697144.64 rows=3 width=20) (actual time=19014.237..19014.237 rows=7 loops=1)
   Sort Key: (substr((public.customer.c_phone)::text, 1, 2))
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=275836 read=52276 dirtied=252
   InitPlan 1 (returns $0)
     ->  Aggregate  (cost=52926.22..52926.23 rows=1 width=4) (actual time=939.626..939.626 rows=1 loops=1)
           Buffers: shared hit=35203 read=1138
           ->  Bitmap Heap Scan on customer  (cost=6650.51..51969.90 rows=382529 width=4) (actual time=190.392..792.548 rows=381228 loops=1)
                 Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,24,31,27,22,26,32}'::text[])) AND (c_acctbal > 0::double precision))
                 Buffers: shared hit=35203 read=1138
                 ->  Bitmap Index Scan on customer_c_phone_idx_c_acctbal  (cost=0.00..6554.88 rows=382529 width=0) (actual time=175.072..175.072 rows=381228 loops=1)
                       Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{33,24,31,27,22,26,32}'::text[]))
                       Buffers: shared hit=11 read=1053
   ->  HashAggregate  (cost=644218.33..644218.37 rows=3 width=20) (actual time=19014.163..19014.165 rows=7 loops=1)
         Buffers: shared hit=275834 read=52276 dirtied=252
         ->  Hash Anti Join  (cost=600177.01..643775.22 rows=59081 width=20) (actual time=18242.681..18971.363 rows=63350 loops=1)
               Hash Cond: (public.customer.c_custkey = orders.o_custkey)
               Buffers: shared hit=275834 read=52276 dirtied=252
               ->  Bitmap Heap Scan on customer  (cost=2911.80..41872.07 rows=140277 width=24) (actual time=1063.191..1393.438 rows=190600 loops=1)
                     Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,24,31,27,22,26,32}'::text[])) AND (c_acctbal > $0))
                     Buffers: shared hit=70377 read=1676
                     ->  Bitmap Index Scan on customer_c_phone_idx  (cost=0.00..2876.73 rows=140277 width=0) (actual time=1040.639..1040.639 rows=190600 loops=1)
                           Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{33,24,31,27,22,26,32}'::text[])) AND (c_acctbal > $0))
                           Buffers: shared hit=35213 read=1676
               ->  Hash  (cost=407703.43..407703.43 rows=15164943 width=4) (actual time=17165.603..17165.603 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 527872kB
                     Buffers: shared hit=205454 read=50600 dirtied=252
                     ->  Seq Scan on orders  (cost=0.00..407703.43 rows=15164943 width=4) (actual time=0.037..7724.501 rows=15015000 loops=1)
                           Buffers: shared hit=205454 read=50600 dirtied=252
 Total runtime: 19098.045 ms
(30 rows)

COMMIT;
COMMIT