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 ('REG AIR', 'FOB')
	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=988024.71..988024.71 rows=1 width=27) (actual time=22160.125..22160.126 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=796964 read=556977 written=621
   ->  HashAggregate  (cost=988024.69..988024.70 rows=1 width=27) (actual time=22160.057..22160.058 rows=2 loops=1)
         Group Key: lineitem.l_shipmode
         Buffers: shared hit=796959 read=556977 written=621
         ->  Hash Join  (cost=596085.37..982893.32 rows=293221 width=27) (actual time=10483.554..21897.709 rows=312567 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=796959 read=556977 written=621
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.43..377645.23 rows=293221 width=15) (actual time=0.169..11052.792 rows=312567 loops=1)
                     Filter: ((l_shipmode = ANY ('{"REG AIR",FOB}'::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: 6876823
                     Buffers: shared hit=603703 read=494682 written=621
               ->  Hash  (cost=406897.75..406897.75 rows=15134975 width=20) (actual time=10398.823..10398.823 rows=15000000 loops=1)
                     Buckets: 16777216  Batches: 1  Memory Usage: 892791kB
                     Buffers: shared hit=193253 read=62295
                     ->  Seq Scan on orders  (cost=0.00..406897.75 rows=15134975 width=20) (actual time=0.027..4896.688 rows=15000000 loops=1)
                           Buffers: shared hit=193253 read=62295
 Planning time: 3.057 ms
 Execution time: 22179.331 ms
(21 rows)

COMMIT;
COMMIT