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 '1994-05-01'
	and l_shipdate < cast(date '1994-05-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1177160.70..1177160.71 rows=1 width=29) (actual time=7258.932..7258.932 rows=1 loops=1)
   Buffers: shared hit=227874 read=231788 written=388
   ->  Hash Join  (cost=101904.81..1163559.78 rows=777195 width=29) (actual time=2180.501..6879.524 rows=773623 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=227874 read=231788 written=388
         ->  Bitmap Heap Scan on lineitem  (cost=16382.81..1066379.86 rows=777195 width=12) (actual time=641.860..4227.789 rows=773623 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-05-01'::date) AND (l_shipdate < '1994-06-01'::date))
               Heap Blocks: exact=417021
               Buffers: shared hit=218724 read=200413 written=326
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16188.52 rows=777195 width=0) (actual time=434.901..434.901 rows=782964 loops=1)
                     Index Cond: ((l_shipdate >= '1994-05-01'::date) AND (l_shipdate < '1994-06-01'::date))
                     Buffers: shared read=2116 written=6
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1524.350..1524.350 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=9147 read=31375 written=62
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..836.302 rows=2000000 loops=1)
                     Buffers: shared hit=9147 read=31375 written=62
 Planning time: 3.254 ms
 Execution time: 7264.209 ms
(19 rows)

COMMIT;
COMMIT