BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	100.00 * sum(case
		when p_type like 'PROMO%'
			then l_extendedprice * (1 - l_discount)
		else 0
	end) / sum(l_extendedprice * (1 - l_discount)) as promo_revenue
from
	lineitem,
	part
where
	l_partkey = p_partkey
	and l_shipdate >= date '1995-07-01'
	and l_shipdate < cast(date '1995-07-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1185888.26..1185888.28 rows=1 width=29) (actual time=8830.150..8830.150 rows=1 loops=1)
   Buffers: shared hit=227113 read=231623 written=104
   ->  Hash Join  (cost=102447.63..1171859.13 rows=801665 width=29) (actual time=3195.856..8438.238 rows=773707 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=227113 read=231623 written=104
         ->  Bitmap Heap Scan on lineitem  (cost=16925.63..1074312.15 rows=801665 width=12) (actual time=1255.272..5776.002 rows=773707 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-07-01'::date) AND (l_shipdate < '1995-08-01'::date))
               Heap Blocks: exact=416095
               Buffers: shared hit=225089 read=193122 written=78
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16725.22 rows=801665 width=0) (actual time=960.902..960.902 rows=780709 loops=1)
                     Index Cond: ((l_shipdate >= '1995-07-01'::date) AND (l_shipdate < '1995-08-01'::date))
                     Buffers: shared read=2116 written=3
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1714.969..1714.969 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=2021 read=38501 written=26
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.031..1013.524 rows=2000000 loops=1)
                     Buffers: shared hit=2021 read=38501 written=26
 Planning time: 4.748 ms
 Execution time: 8838.735 ms
(19 rows)

COMMIT;
COMMIT