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 '1997-08-01'
	and l_shipdate < cast(date '1997-08-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1156656.13..1156656.14 rows=1 width=29) (actual time=8784.873..8784.873 rows=1 loops=1)
   Buffers: shared hit=245956 read=211999 dirtied=426 written=265
   ->  Hash Join  (cost=101159.24..1143699.85 rows=740359 width=29) (actual time=3077.665..8340.361 rows=772354 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=245956 read=211999 dirtied=426 written=265
         ->  Bitmap Heap Scan on lineitem  (cost=15637.24..1047072.46 rows=740359 width=12) (actual time=916.007..5332.577 rows=772354 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-08-01'::date) AND (l_shipdate < '1997-09-01'::date))
               Heap Blocks: exact=415317
               Buffers: shared hit=213656 read=203774 dirtied=426 written=261
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15452.16 rows=740359 width=0) (actual time=579.370..579.370 rows=778639 loops=1)
                     Index Cond: ((l_shipdate >= '1997-08-01'::date) AND (l_shipdate < '1997-09-01'::date))
                     Buffers: shared hit=3 read=2110 written=14
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2146.019..2146.019 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=32297 read=8225 written=4
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.022..1154.748 rows=2000000 loops=1)
                     Buffers: shared hit=32297 read=8225 written=4
 Planning time: 4.038 ms
 Execution time: 8792.276 ms
(19 rows)

COMMIT;
COMMIT