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 '1997-05-01'
	and l_shipdate < cast(date '1997-05-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1172970.18..1172970.19 rows=1 width=29) (actual time=7724.262..7724.262 rows=1 loops=1)
   Buffers: shared hit=304182 read=151843 dirtied=174
   ->  Hash Join  (cost=102174.07..1159223.70 rows=785513 width=29) (actual time=2229.226..7321.544 rows=774552 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=304182 read=151843 dirtied=174
         ->  Bitmap Heap Scan on lineitem  (cost=16652.07..1061919.01 rows=785513 width=12) (actual time=495.975..4641.708 rows=774552 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-05-01'::date) AND (l_shipdate < '1997-06-01'::date))
               Heap Blocks: exact=413382
               Buffers: shared hit=263666 read=151834 dirtied=174
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16455.69 rows=785513 width=0) (actual time=339.548..339.548 rows=775346 loops=1)
                     Index Cond: ((l_shipdate >= '1997-05-01'::date) AND (l_shipdate < '1997-06-01'::date))
                     Buffers: shared hit=2 read=2116
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1721.336..1721.336 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=40513 read=9
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.018..747.537 rows=2000000 loops=1)
                     Buffers: shared hit=40513 read=9
 Planning time: 2.993 ms
 Execution time: 7730.878 ms
(19 rows)

COMMIT;
COMMIT