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', 'FOB')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1996-01-01'
	and l_receiptdate < date '1996-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=986290.24..986290.24 rows=1 width=27) (actual time=27012.812..27012.813 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=784521 read=583090 dirtied=754 written=17313
   ->  HashAggregate  (cost=986290.22..986290.23 rows=1 width=27) (actual time=27012.747..27012.748 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=784516 read=583090 dirtied=754 written=17313
         ->  Hash Join  (cost=594902.76..981156.02 rows=293383 width=27) (actual time=12516.983..26704.515 rows=312463 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=784516 read=583090 dirtied=754 written=17313
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..377085.47 rows=293383 width=15) (actual time=0.100..13678.608 rows=312463 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,FOB}'::bpchar[])) AND (l_receiptdate >= '1996-01-01'::date) AND (l_receiptdate < '1997-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6884306
                     Buffers: shared hit=600435 read=512127 dirtied=754 written=17274
               ->  Hash  (cost=406090.48..406090.48 rows=15104948 width=20) (actual time=11900.405..11900.405 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=184078 read=70963 written=39
                     ->  Seq Scan on orders  (cost=0.00..406090.48 rows=15104948 width=20) (actual time=0.025..5579.742 rows=15015000 loops=1)
                           Buffers: shared hit=184078 read=70963 written=39
 Planning time: 3.315 ms
 Execution time: 27043.128 ms
(21 rows)

COMMIT;
COMMIT