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 ('SHIP', 'RAIL')
	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=986437.11..986437.11 rows=1 width=27) (actual time=31994.580..31994.581 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=533981 read=833814 dirtied=318 written=45
   ->  HashAggregate  (cost=986437.09..986437.10 rows=1 width=27) (actual time=31994.490..31994.491 rows=2 loops=1)
         Buffers: shared hit=533976 read=833814 dirtied=318 written=45
         ->  Hash Join  (cost=594902.33..981317.20 rows=292565 width=27) (actual time=14032.186..31560.373 rows=311288 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=533976 read=833814 dirtied=318 written=45
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..377272.21 rows=292565 width=15) (actual time=0.188..16320.791 rows=311288 loops=1)
                     Filter: ((l_shipmode = ANY ('{SHIP,RAIL}'::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: 6885481
                     Buffers: shared hit=279795 read=832951 dirtied=59 written=45
               ->  Hash  (cost=406090.48..406090.48 rows=15104948 width=20) (actual time=14020.836..14020.836 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 762481kB
                     Buffers: shared hit=254178 read=863 dirtied=259
                     ->  Seq Scan on orders  (cost=0.00..406090.48 rows=15104948 width=20) (actual time=0.013..5616.667 rows=15015000 loops=1)
                           Buffers: shared hit=254178 read=863 dirtied=259
 Total runtime: 32135.841 ms
(19 rows)

COMMIT;
COMMIT