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 '1995-02-01'
	and l_shipdate < cast(date '1995-02-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1161121.10..1161121.11 rows=1 width=29) (actual time=8483.035..8483.036 rows=1 loops=1)
   Buffers: shared hit=218577 read=218946 written=245
   ->  Hash Join  (cost=101202.08..1148105.33 rows=743758 width=29) (actual time=2353.938..8070.847 rows=698188 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=218577 read=218946 written=245
         ->  Bitmap Heap Scan on lineitem  (cost=15680.08..1051426.96 rows=743758 width=12) (actual time=468.406..5205.902 rows=698188 loops=1)
               Recheck Cond: ((l_shipdate >= '1995-02-01'::date) AND (l_shipdate < '1995-03-01'::date))
               Heap Blocks: exact=395088
               Buffers: shared hit=214960 read=182038 written=204
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15494.15 rows=743758 width=0) (actual time=316.657..316.657 rows=706623 loops=1)
                     Index Cond: ((l_shipdate >= '1995-02-01'::date) AND (l_shipdate < '1995-03-01'::date))
                     Buffers: shared read=1910 written=2
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1877.349..1877.349 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=3614 read=36908 written=41
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.017..1153.452 rows=2000000 loops=1)
                     Buffers: shared hit=3614 read=36908 written=41
 Planning time: 3.155 ms
 Execution time: 8487.391 ms
(19 rows)

COMMIT;
COMMIT