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 '1997-01-01'
	and l_receiptdate < date '1997-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=985268.97..985268.98 rows=1 width=27) (actual time=46653.708..46653.708 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=384851 read=978613 dirtied=27 written=1787
   ->  HashAggregate  (cost=985268.95..985268.96 rows=1 width=27) (actual time=46653.593..46653.595 rows=2 loops=1)
         Buffers: shared hit=384846 read=978613 dirtied=27 written=1787
         ->  Hash Join  (cost=593719.70..980213.48 rows=288884 width=27) (actual time=17895.772..45961.168 rows=310928 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=384846 read=978613 dirtied=27 written=1787
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..377466.16 rows=288884 width=15) (actual time=0.715..26474.686 rows=310928 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,AIR}'::bpchar[])) AND (l_receiptdate >= '1997-01-01'::date) AND (l_receiptdate < '1998-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6878937
                     Buffers: shared hit=197327 read=911595 written=112
               ->  Hash  (cost=405283.20..405283.20 rows=15074920 width=20) (actual time=17886.289..17886.289 rows=15000000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 761719kB
                     Buffers: shared hit=187516 read=67018 dirtied=27 written=1675
                     ->  Seq Scan on orders  (cost=0.00..405283.20 rows=15074920 width=20) (actual time=0.026..9268.927 rows=15000000 loops=1)
                           Buffers: shared hit=187516 read=67018 dirtied=27 written=1675
 Total runtime: 46831.611 ms
(19 rows)

COMMIT;
COMMIT