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 '1995-12-01'
	and l_shipdate < cast(date '1995-12-01' + interval '1 month' as date);
                                                                                QUERY PLAN                                                                                 
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1172076.46..1172076.48 rows=1 width=29) (actual time=14986.098..14986.098 rows=1 loops=1)
   Buffers: shared hit=243235 read=213066 written=220
   ->  Hash Join  (cost=101919.55..1158505.02 rows=775511 width=29) (actual time=9085.827..14591.963 rows=771980 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=243235 read=213066 written=220
         ->  Bitmap Heap Scan on lineitem  (cost=16397.55..1061350.36 rows=775511 width=12) (actual time=7474.212..12221.553 rows=771980 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-12-01'::date) AND (l_shipdate < '1996-01-01'::date))
               Heap Blocks: exact=413664
               Buffers: shared hit=205657 read=210119 written=220
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16203.68 rows=775511 width=0) (actual time=7009.617..7009.617 rows=776674 loops=1)
                     Index Cond: ((l_shipdate >= '1995-12-01'::date) AND (l_shipdate < '1996-01-01'::date))
                     Buffers: shared read=2112
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1594.761..1594.761 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=37575 read=2947
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.045..851.028 rows=2000000 loops=1)
                     Buffers: shared hit=37575 read=2947
 Planning time: 2.777 ms
 Execution time: 14994.008 ms
(19 rows)

COMMIT;
COMMIT