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 ('SHIP', 'MAIL')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1995-01-01'
	and l_receiptdate < date '1995-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                           
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=984910.08..984910.08 rows=1 width=27) (actual time=23797.998..23797.999 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=903610 read=463549 dirtied=509 written=1548
   ->  HashAggregate  (cost=984910.06..984910.07 rows=1 width=27) (actual time=23797.936..23797.937 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=903605 read=463549 dirtied=509 written=1548
         ->  Hash Join  (cost=593720.13..979814.27 rows=291188 width=27) (actual time=10969.361..23494.766 rows=311118 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=903605 read=463549 dirtied=509 written=1548
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..376994.94 rows=291188 width=15) (actual time=0.176..12161.290 rows=311118 loops=1)
                     Filter: ((l_shipmode = ANY ('{SHIP,MAIL}'::bpchar[])) AND (l_receiptdate >= '1995-01-01'::date) AND (l_receiptdate < '1996-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6878747
                     Buffers: shared hit=702913 read=409704 dirtied=508 written=233
               ->  Hash  (cost=405283.20..405283.20 rows=15074920 width=20) (actual time=10817.320..10817.320 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=200689 read=53845 dirtied=1 written=1315
                     ->  Seq Scan on orders  (cost=0.00..405283.20 rows=15074920 width=20) (actual time=0.019..5087.572 rows=15000000 loops=1)
                           Buffers: shared hit=200689 read=53845 dirtied=1 written=1315
 Planning time: 3.450 ms
 Execution time: 23810.319 ms
(21 rows)

COMMIT;
COMMIT