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 '1994-08-01'
	and l_shipdate < cast(date '1994-08-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1184501.16..1184501.17 rows=1 width=29) (actual time=6778.063..6778.063 rows=1 loops=1)
   Buffers: shared hit=266187 read=193062 written=693
   ->  Hash Join  (cost=102378.87..1170527.95 rows=798469 width=29) (actual time=2138.669..6392.277 rows=774757 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=266187 read=193062 written=693
         ->  Bitmap Heap Scan on lineitem  (cost=16856.87..1073028.92 rows=798469 width=12) (actual time=579.819..4109.478 rows=774757 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
               Heap Blocks: exact=416605
               Buffers: shared hit=251063 read=167661 written=653
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16657.26 rows=798469 width=0) (actual time=391.176..391.176 rows=781693 loops=1)
                     Index Cond: ((l_shipdate >= '1994-08-01'::date) AND (l_shipdate < '1994-09-01'::date))
                     Buffers: shared read=2119 written=5
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1542.453..1542.453 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=15121 read=25401 written=40
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.010..816.263 rows=2000000 loops=1)
                     Buffers: shared hit=15121 read=25401 written=40
 Planning time: 3.554 ms
 Execution time: 6785.663 ms
(19 rows)

COMMIT;
COMMIT