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', 'AIR')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1996-01-01'
	and l_receiptdate < date '1996-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=983847.32..983847.32 rows=1 width=27) (actual time=22007.582..22007.582 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=768221 read=594925 dirtied=626 written=1509
   ->  HashAggregate  (cost=983847.30..983847.31 rows=1 width=27) (actual time=22007.526..22007.527 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=768216 read=594925 dirtied=626 written=1509
         ->  Hash Join  (cost=593129.99..978752.63 rows=291124 width=27) (actual time=9885.760..21707.200 rows=312544 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=768216 read=594925 dirtied=626 written=1509
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..376525.44 rows=291124 width=15) (actual time=0.223..11453.565 rows=312544 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,AIR}'::bpchar[])) AND (l_receiptdate >= '1996-01-01'::date) AND (l_receiptdate < '1997-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6877463
                     Buffers: shared hit=547581 read=561276 dirtied=484 written=11
               ->  Hash  (cost=404880.36..404880.36 rows=15059936 width=20) (actual time=9766.958..9766.958 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=220632 read=33649 dirtied=142 written=1498
                     ->  Seq Scan on orders  (cost=0.00..404880.36 rows=15059936 width=20) (actual time=0.017..4763.864 rows=15000000 loops=1)
                           Buffers: shared hit=220632 read=33649 dirtied=142 written=1498
 Planning time: 2.716 ms
 Execution time: 22038.774 ms
(21 rows)

COMMIT;
COMMIT