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 ('REG 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=991962.88..991962.89 rows=1 width=27) (actual time=27259.647..27259.648 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=599165 read=767320 written=3936
   ->  HashAggregate  (cost=991962.86..991962.87 rows=1 width=27) (actual time=27259.585..27259.586 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=599160 read=767320 written=3936
         ->  Hash Join  (cost=598445.93..986871.59 rows=290930 width=27) (actual time=12191.027..26952.472 rows=311693 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=599160 read=767320 written=3936
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..379334.53 rows=290930 width=15) (actual time=0.128..14395.313 rows=311693 loops=1)
                     Filter: ((l_shipmode = ANY ('{"REG 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: 6884977
                     Buffers: shared hit=460599 read=649318 written=3773
               ->  Hash  (cost=408509.11..408509.11 rows=15194911 width=20) (actual time=11168.375..11168.375 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=138558 read=118002 written=163
                     ->  Seq Scan on orders  (cost=0.00..408509.11 rows=15194911 width=20) (actual time=0.021..5886.699 rows=15015000 loops=1)
                           Buffers: shared hit=138558 read=118002 written=163
 Planning time: 3.676 ms
 Execution time: 27292.976 ms
(21 rows)

COMMIT;
COMMIT