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 '1997-07-01'
	and l_shipdate < cast(date '1997-07-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1178018.10..1178018.11 rows=1 width=29) (actual time=8340.035..8340.035 rows=1 loops=1)
   Buffers: shared hit=1099 read=454213
   ->  Hash Join  (cost=102466.37..1164038.92 rows=798810 width=29) (actual time=1990.188..7948.877 rows=774543 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=1099 read=454213
         ->  Bitmap Heap Scan on lineitem  (cost=16944.37..1066534.77 rows=798810 width=12) (actual time=462.013..5607.381 rows=774543 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-07-01'::date) AND (l_shipdate < '1997-08-01'::date))
               Heap Blocks: exact=412669
               Buffers: shared hit=1094 read=413693
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16744.66 rows=798810 width=0) (actual time=287.730..287.730 rows=774543 loops=1)
                     Index Cond: ((l_shipdate >= '1997-07-01'::date) AND (l_shipdate < '1997-08-01'::date))
                     Buffers: shared hit=671 read=1447
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1514.331..1514.331 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=2 read=40520
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..713.578 rows=2000000 loops=1)
                     Buffers: shared hit=2 read=40520
 Planning time: 4.157 ms
 Execution time: 8342.926 ms
(19 rows)

COMMIT;
COMMIT