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 '1994-02-01'
	and l_shipdate < cast(date '1994-02-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1123838.89..1123838.90 rows=1 width=29) (actual time=8067.064..8067.064 rows=1 loops=1)
   Buffers: shared hit=112807 read=324357 written=8841
   ->  Hash Join  (cost=99780.27..1112007.68 rows=676069 width=29) (actual time=2158.443..7701.669 rows=698275 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=112807 read=324357 written=8841
         ->  Bitmap Heap Scan on lineitem  (cost=14258.27..1016344.64 rows=676069 width=12) (actual time=492.876..5329.611 rows=698275 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-02-01'::date) AND (l_shipdate < '1994-03-01'::date))
               Heap Blocks: exact=394727
               Buffers: shared hit=112049 read=284590 written=8837
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..14089.26 rows=676069 width=0) (actual time=309.519..309.519 rows=706678 loops=1)
                     Index Cond: ((l_shipdate >= '1994-02-01'::date) AND (l_shipdate < '1994-03-01'::date))
                     Buffers: shared read=1912
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1649.635..1649.635 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=755 read=39767 written=4
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.016..949.642 rows=2000000 loops=1)
                     Buffers: shared hit=755 read=39767 written=4
 Planning time: 3.139 ms
 Execution time: 8072.814 ms
(19 rows)

COMMIT;
COMMIT