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 ('RAIL', 'SHIP')
	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=982353.97..982353.98 rows=1 width=27) (actual time=24670.773..24670.774 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=797511 read=561151 written=105
   ->  HashAggregate  (cost=982353.95..982353.96 rows=1 width=27) (actual time=24670.710..24670.712 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=797506 read=561151 written=105
         ->  Hash Join  (cost=591949.71..977192.06 rows=294965 width=27) (actual time=12404.949..24369.877 rows=311826 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=797506 read=561151 written=105
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..376025.13 rows=294965 width=15) (actual time=0.099..11645.817 rows=311826 loops=1)
                     Filter: ((l_shipmode = ANY ('{RAIL,SHIP}'::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: 6878144
                     Buffers: shared hit=580715 read=524164 written=96
               ->  Hash  (cost=404074.68..404074.68 rows=15029968 width=20) (actual time=10585.492..10585.492 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=216788 read=36987 written=9
                     ->  Seq Scan on orders  (cost=0.00..404074.68 rows=15029968 width=20) (actual time=0.022..5218.917 rows=15000000 loops=1)
                           Buffers: shared hit=216788 read=36987 written=9
 Planning time: 2.629 ms
 Execution time: 24689.289 ms
(21 rows)

COMMIT;
COMMIT