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 '1993-01-01'
	and l_receiptdate < date '1993-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=991691.82..991691.82 rows=1 width=27) (actual time=22271.033..22271.033 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=734299 read=639291 dirtied=112 written=494
   ->  HashAggregate  (cost=991691.80..991691.81 rows=1 width=27) (actual time=22270.977..22270.979 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=734294 read=639291 dirtied=112 written=494
         ->  Hash Join  (cost=597855.79..986564.82 rows=292970 width=27) (actual time=10194.675..21978.567 rows=312426 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=734294 read=639291 dirtied=112 written=494
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..379554.15 rows=292970 width=15) (actual time=0.162..11402.249 rows=312426 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,FOB}'::bpchar[])) AND (l_receiptdate >= '1993-01-01'::date) AND (l_receiptdate < '1994-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6876970
                     Buffers: shared hit=527761 read=589514 dirtied=112 written=372
               ->  Hash  (cost=408106.27..408106.27 rows=15179927 width=20) (actual time=10087.855..10087.855 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=206530 read=49777 written=122
                     ->  Seq Scan on orders  (cost=0.00..408106.27 rows=15179927 width=20) (actual time=0.019..4864.241 rows=15000000 loops=1)
                           Buffers: shared hit=206530 read=49777 written=122
 Planning time: 2.639 ms
 Execution time: 22287.511 ms
(21 rows)

COMMIT;
COMMIT