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 '1993-10-01'
	and l_shipdate < cast(date '1993-10-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1165421.89..1165421.91 rows=1 width=29) (actual time=11165.947..11165.947 rows=1 loops=1)
   Buffers: shared hit=201473 read=253822 written=31
   ->  Hash Join  (cost=101778.97..1151994.86 rows=767259 width=29) (actual time=3880.344..10710.684 rows=773403 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=201473 read=253822 written=31
         ->  Bitmap Heap Scan on lineitem  (cost=16256.97..1054963.97 rows=767259 width=12) (actual time=1138.606..6546.450 rows=773403 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-10-01'::date) AND (l_shipdate < '1993-11-01'::date))
               Heap Blocks: exact=412655
               Buffers: shared hit=199015 read=215755 written=15
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16065.16 rows=767259 width=0) (actual time=700.048..700.048 rows=774864 loops=1)
                     Index Cond: ((l_shipdate >= '1993-10-01'::date) AND (l_shipdate < '1993-11-01'::date))
                     Buffers: shared read=2115
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2726.009..2726.009 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=2455 read=38067 written=16
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.026..1582.399 rows=2000000 loops=1)
                     Buffers: shared hit=2455 read=38067 written=16
 Planning time: 5.102 ms
 Execution time: 11169.190 ms
(19 rows)

COMMIT;
COMMIT