BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	l_shipmode,
	sum(case
		when o_orderpriority = '1-URGENT'
			or o_orderpriority = '2-HIGH'
			then 1
		else 0
	end) as high_line_count,
	sum(case
		when o_orderpriority <> '1-URGENT'
			and o_orderpriority <> '2-HIGH'
			then 1
		else 0
	end) as low_line_count
from
	orders,
	lineitem
where
	o_orderkey = l_orderkey
	and l_shipmode in ('AIR', 'RAIL')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1994-01-01'
	and l_receiptdate < date '1994-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=985080.22..985080.23 rows=1 width=27) (actual time=22863.794..22863.795 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=855960 read=507756 written=6397
   ->  HashAggregate  (cost=985080.20..985080.21 rows=1 width=27) (actual time=22863.735..22863.736 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=855955 read=507756 written=6397
         ->  Hash Join  (cost=594310.27..980034.13 rows=288347 width=27) (actual time=10915.477..22562.274 rows=312115 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=855955 read=507756 written=6397
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..376713.44 rows=288347 width=15) (actual time=0.097..11314.423 rows=312115 loops=1)
                     Filter: ((l_shipmode = ANY ('{AIR,RAIL}'::bpchar[])) AND (l_receiptdate >= '1994-01-01'::date) AND (l_receiptdate < '1995-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6884750
                     Buffers: shared hit=636932 read=471989 written=6397
               ->  Hash  (cost=405686.04..405686.04 rows=15089904 width=20) (actual time=10812.485..10812.485 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=219020 read=35767
                     ->  Seq Scan on orders  (cost=0.00..405686.04 rows=15089904 width=20) (actual time=0.022..5383.434 rows=15015000 loops=1)
                           Buffers: shared hit=219020 read=35767
 Planning time: 3.389 ms
 Execution time: 22881.917 ms
(21 rows)

COMMIT;
COMMIT