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', 'REG AIR')
	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=993790.48..993790.48 rows=1 width=27) (actual time=44773.232..44773.232 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=1085039 read=282327 written=1
   ->  HashAggregate  (cost=993790.46..993790.47 rows=1 width=27) (actual time=44773.121..44773.121 rows=2 loops=1)
         Buffers: shared hit=1085034 read=282327 written=1
         ->  Hash Join  (cost=599625.78..988708.18 rows=290416 width=27) (actual time=16888.612..44136.565 rows=311248 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=1085034 read=282327 written=1
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..380006.90 rows=290416 width=15) (actual time=0.104..25784.091 rows=311248 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,"REG AIR"}'::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: 6885477
                     Buffers: shared hit=834529 read=275763 written=1
               ->  Hash  (cost=409314.79..409314.79 rows=15224879 width=20) (actual time=16877.718..16877.718 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 762481kB
                     Buffers: shared hit=250502 read=6564
                     ->  Seq Scan on orders  (cost=0.00..409314.79 rows=15224879 width=20) (actual time=0.037..8348.887 rows=15015000 loops=1)
                           Buffers: shared hit=250502 read=6564
 Total runtime: 44912.638 ms
(19 rows)

COMMIT;
COMMIT