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 '1993-04-01'
	and l_shipdate < cast(date '1993-04-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1153783.68..1153783.70 rows=1 width=29) (actual time=6998.230..6998.230 rows=1 loops=1)
   Buffers: shared hit=311118 read=137300 dirtied=193 written=2114
   ->  Hash Join  (cost=101312.63..1140749.91 rows=744787 width=29) (actual time=2212.041..6610.513 rows=749071 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=311118 read=137300 dirtied=193 written=2114
         ->  Bitmap Heap Scan on lineitem  (cost=15790.63..1044056.10 rows=744787 width=12) (actual time=487.337..4178.000 rows=749071 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
               Heap Blocks: exact=405842
               Buffers: shared hit=280202 read=127691 dirtied=193 written=1719
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15604.43 rows=744787 width=0) (actual time=333.046..333.046 rows=750270 loops=1)
                     Index Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
                     Buffers: shared hit=101 read=1950 written=69
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1713.118..1713.118 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=30913 read=9609 written=395
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.020..998.941 rows=2000000 loops=1)
                     Buffers: shared hit=30913 read=9609 written=395
 Planning time: 2.920 ms
 Execution time: 7001.772 ms
(19 rows)

COMMIT;
COMMIT