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', 'TRUCK')
	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=984958.35..984958.35 rows=1 width=27) (actual time=22275.796..22275.797 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=1290908 read=72555 written=1261
   ->  HashAggregate  (cost=984958.33..984958.34 rows=1 width=27) (actual time=22275.732..22275.733 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=1290903 read=72555 written=1261
         ->  Hash Join  (cost=593720.13..979880.02 rows=290189 width=27) (actual time=10753.220..21985.033 rows=311755 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=1290903 read=72555 written=1261
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..377091.91 rows=290189 width=15) (actual time=0.082..10711.109 rows=311755 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,TRUCK}'::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: 6878110
                     Buffers: shared hit=1053573 read=55348 written=21
               ->  Hash  (cost=405283.20..405283.20 rows=15074920 width=20) (actual time=10594.949..10594.949 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=237327 read=17207 written=1240
                     ->  Seq Scan on orders  (cost=0.00..405283.20 rows=15074920 width=20) (actual time=0.021..5300.380 rows=15000000 loops=1)
                           Buffers: shared hit=237327 read=17207 written=1240
 Planning time: 2.889 ms
 Execution time: 22319.703 ms
(21 rows)

COMMIT;
COMMIT