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 ('MAIL', 'AIR')
	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=990777.44..990777.44 rows=1 width=27) (actual time=23935.637..23935.638 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=1020784 read=345448 written=6006
   ->  HashAggregate  (cost=990777.42..990777.43 rows=1 width=27) (actual time=23935.575..23935.576 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=1020779 read=345448 written=6006
         ->  Hash Join  (cost=597855.79..985638.63 rows=293645 width=27) (actual time=10777.538..23610.579 rows=311141 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=1020779 read=345448 written=6006
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..378606.87 rows=293645 width=15) (actual time=0.093..12349.309 rows=311141 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,AIR}'::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: 6878255
                     Buffers: shared hit=870873 read=239044 written=308
               ->  Hash  (cost=408106.27..408106.27 rows=15179927 width=20) (actual time=10545.066..10545.066 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=149903 read=106404 written=5698
                     ->  Seq Scan on orders  (cost=0.00..408106.27 rows=15179927 width=20) (actual time=0.022..5545.152 rows=15000000 loops=1)
                           Buffers: shared hit=149903 read=106404 written=5698
 Planning time: 2.959 ms
 Execution time: 23958.470 ms
(21 rows)

COMMIT;
COMMIT