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 ('AIR', 'MAIL')
	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=979933.17..979933.17 rows=1 width=27) (actual time=22581.516..22581.517 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=345229 read=1009261
   ->  HashAggregate  (cost=979933.15..979933.16 rows=1 width=27) (actual time=22581.423..22581.424 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=345224 read=1009261
         ->  Hash Join  (cost=591359.57..974887.29 rows=288335 width=27) (actual time=10157.896..22291.328 rows=311237 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=345224 read=1009261
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..374517.68 rows=288335 width=15) (actual time=0.465..11743.784 rows=311237 loops=1)
                     Filter: ((l_shipmode = ANY ('{AIR,MAIL}'::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: 6886167
                     Buffers: shared hit=101728 read=999232
               ->  Hash  (cost=403671.84..403671.84 rows=15014984 width=20) (actual time=10044.895..10044.895 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=243493 read=10029
                     ->  Seq Scan on orders  (cost=0.00..403671.84 rows=15014984 width=20) (actual time=0.014..4557.007 rows=15015000 loops=1)
                           Buffers: shared hit=243493 read=10029
 Planning time: 4.171 ms
 Execution time: 22589.344 ms
(21 rows)

COMMIT;
COMMIT