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
				('24', '31', '22', '25', '14', '33', '20')
			and c_acctbal > (
				select
					avg(c_acctbal)
				from
					customer
				where
					c_acctbal > 0.00
					and substr(c_phone, 1, 2) in
						('24', '31', '22', '25', '14', '33', '20')
			)
			and not exists (
				select
					*
				from
					orders
				where
					o_custkey = c_custkey
			)
	) as vip
group by
	cntrycode
order by
	cntrycode;
                                                                              QUERY PLAN                                                                              
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=694839.09..694839.10 rows=3 width=20) (actual time=14323.884..14323.885 rows=7 loops=1)
   Sort Key: (substr((public.customer.c_phone)::text, 1, 2))
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=325504 read=1607 dirtied=49
   InitPlan 1 (returns $0)
     ->  Aggregate  (cost=52953.35..52953.36 rows=1 width=4) (actual time=759.221..759.222 rows=1 loops=1)
           Buffers: shared hit=35291 read=1050
           ->  Bitmap Heap Scan on customer  (cost=6675.16..51996.81 rows=382615 width=4) (actual time=161.459..642.305 rows=381328 loops=1)
                 Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,31,22,25,14,33,20}'::text[])) AND (c_acctbal > 0::double precision))
                 Buffers: shared hit=35291 read=1050
                 ->  Bitmap Index Scan on customer_c_phone_idx_c_acctbal  (cost=0.00..6579.51 rows=382615 width=0) (actual time=147.369..147.369 rows=381328 loops=1)
                       Index Cond: (substr((c_phone)::text, 1, 2) = ANY ('{24,31,22,25,14,33,20}'::text[]))
                       Buffers: shared hit=14 read=1050
   ->  HashAggregate  (cost=641885.67..641885.71 rows=3 width=20) (actual time=14323.806..14323.808 rows=7 loops=1)
         Buffers: shared hit=325502 read=1607 dirtied=49
         ->  Hash Anti Join  (cost=597842.41..641442.46 rows=59094 width=20) (actual time=13700.985..14275.131 rows=63567 loops=1)
               Hash Cond: (public.customer.c_custkey = orders.o_custkey)
               Buffers: shared hit=325502 read=1607 dirtied=49
               ->  Bitmap Heap Scan on customer  (cost=2940.08..41901.17 rows=140308 width=24) (actual time=819.493..1049.686 rows=190646 loops=1)
                     Recheck Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,31,22,25,14,33,20}'::text[])) AND (c_acctbal > $0))
                     Buffers: shared hit=70477 read=1588
                     ->  Bitmap Index Scan on customer_c_phone_idx  (cost=0.00..2905.01 rows=140308 width=0) (actual time=811.457..811.457 rows=190646 loops=1)
                           Index Cond: ((substr((c_phone)::text, 1, 2) = ANY ('{24,31,22,25,14,33,20}'::text[])) AND (c_acctbal > $0))
                           Buffers: shared hit=35303 read=1587
               ->  Hash  (cost=406090.48..406090.48 rows=15104948 width=4) (actual time=12869.887..12869.887 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 527872kB
                     Buffers: shared hit=255022 read=19 dirtied=49
                     ->  Seq Scan on orders  (cost=0.00..406090.48 rows=15104948 width=4) (actual time=0.017..5661.967 rows=15015000 loops=1)
                           Buffers: shared hit=255022 read=19 dirtied=49
 Total runtime: 14415.318 ms
(30 rows)

COMMIT;
COMMIT