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', 'FOB')
	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=988873.80..988873.80 rows=1 width=27) (actual time=27114.450..27114.451 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=1018866 read=343293 written=7315
   ->  HashAggregate  (cost=988873.78..988873.79 rows=1 width=27) (actual time=27114.363..27114.364 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=1018861 read=343293 written=7315
         ->  Hash Join  (cost=596675.51..983785.18 rows=290777 width=27) (actual time=13662.293..26770.509 rows=311580 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=1018861 read=343293 written=7315
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..378023.32 rows=290777 width=15) (actual time=0.209..12551.033 rows=311580 loops=1)
                     Filter: ((l_shipmode = ANY ('{"REG AIR",FOB}'::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: 6884982
                     Buffers: shared hit=832658 read=273692 written=7178
               ->  Hash  (cost=407300.59..407300.59 rows=15149959 width=20) (actual time=13056.917..13056.917 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=186200 read=69601 written=137
                     ->  Seq Scan on orders  (cost=0.00..407300.59 rows=15149959 width=20) (actual time=0.031..5917.488 rows=15015000 loops=1)
                           Buffers: shared hit=186200 read=69601 written=137
 Planning time: 4.946 ms
 Execution time: 27147.514 ms
(21 rows)

COMMIT;
COMMIT