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=1170513.06..1170513.07 rows=1 width=29) (actual time=6885.377..6885.377 rows=1 loops=1)
   Buffers: shared hit=237704 read=220007 written=104
   ->  Hash Join  (cost=101765.35..1157054.65 rows=769052 width=29) (actual time=2076.015..6501.956 rows=773310 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=237704 read=220007 written=104
         ->  Bitmap Heap Scan on lineitem  (cost=16243.35..1059996.87 rows=769052 width=12) (actual time=464.064..4204.070 rows=773310 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-10-01'::date) AND (l_shipdate < '1993-11-01'::date))
               Heap Blocks: exact=415071
               Buffers: shared hit=235217 read=181969 written=48
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16051.09 rows=769052 width=0) (actual time=311.397..311.397 rows=779381 loops=1)
                     Index Cond: ((l_shipdate >= '1993-10-01'::date) AND (l_shipdate < '1993-11-01'::date))
                     Buffers: shared read=2115 written=2
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1601.305..1601.305 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=2484 read=38038 written=56
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..934.217 rows=2000000 loops=1)
                     Buffers: shared hit=2484 read=38038 written=56
 Planning time: 3.510 ms
 Execution time: 6888.401 ms
(19 rows)

COMMIT;
COMMIT