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 ('RAIL', 'AIR')
	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=985211.90..985211.90 rows=1 width=27) (actual time=23402.803..23402.804 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=895279 read=468437 written=2
   ->  HashAggregate  (cost=985211.88..985211.89 rows=1 width=27) (actual time=23402.739..23402.739 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=895274 read=468437 written=2
         ->  Hash Join  (cost=594310.27..980118.54 rows=291048 width=27) (actual time=10314.781..23107.505 rows=312047 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=895274 read=468437 written=2
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..376713.44 rows=291048 width=15) (actual time=0.295..12491.383 rows=312047 loops=1)
                     Filter: ((l_shipmode = ANY ('{RAIL,AIR}'::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: 6884818
                     Buffers: shared hit=642843 read=466078
               ->  Hash  (cost=405686.04..405686.04 rows=15089904 width=20) (actual time=10217.014..10217.014 rows=15015000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 893553kB
                     Buffers: shared hit=252428 read=2359 written=2
                     ->  Seq Scan on orders  (cost=0.00..405686.04 rows=15089904 width=20) (actual time=0.018..5190.360 rows=15015000 loops=1)
                           Buffers: shared hit=252428 read=2359 written=2
 Planning time: 3.287 ms
 Execution time: 23424.339 ms
(21 rows)

COMMIT;
COMMIT