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 '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=983042.63..983042.63 rows=1 width=27) (actual time=28700.899..28700.900 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=938773 read=424190 dirtied=106 written=88
   ->  HashAggregate  (cost=983042.61..983042.62 rows=1 width=27) (actual time=28700.821..28700.822 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=938768 read=424190 dirtied=106 written=88
         ->  Hash Join  (cost=593129.99..977969.46 rows=289894 width=27) (actual time=11786.256..28287.849 rows=312242 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=938768 read=424190 dirtied=106 written=88
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..375780.71 rows=289894 width=15) (actual time=0.274..16093.391 rows=312242 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,AIR}'::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: 6884941
                     Buffers: shared hit=727197 read=381477 written=88
               ->  Hash  (cost=404880.36..404880.36 rows=15059936 width=20) (actual time=11664.823..11664.823 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=211568 read=42713 dirtied=106
                     ->  Seq Scan on orders  (cost=0.00..404880.36 rows=15059936 width=20) (actual time=0.023..5496.079 rows=15015000 loops=1)
                           Buffers: shared hit=211568 read=42713 dirtied=106
 Planning time: 4.558 ms
 Execution time: 28706.552 ms
(21 rows)

COMMIT;
COMMIT