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=1179613.91..1179613.92 rows=1 width=29) (actual time=11264.931..11264.931 rows=1 loops=1)
   Buffers: shared hit=95889 read=357964 written=7027
   ->  Hash Join  (cost=102544.84..1165569.05 rows=802563 width=29) (actual time=2338.707..10793.821 rows=771322 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=95889 read=357964 written=7027
         ->  Bitmap Heap Scan on lineitem  (cost=17022.84..1068008.61 rows=802563 width=12) (actual time=781.761..7789.637 rows=771322 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-12-01'::date) AND (l_shipdate < '1996-01-01'::date))
               Heap Blocks: exact=411216
               Buffers: shared hit=55368 read=357960 written=7027
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16822.19 rows=802563 width=0) (actual time=574.235..574.235 rows=772110 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=1549.130..1549.130 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=40518 read=4
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.022..743.553 rows=2000000 loops=1)
                     Buffers: shared hit=40518 read=4
 Planning time: 2.970 ms
 Execution time: 11269.827 ms
(19 rows)

COMMIT;
COMMIT