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 '1993-07-01'
	and l_shipdate < cast(date '1993-07-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1155662.38..1155662.39 rows=1 width=29) (actual time=7487.283..7487.283 rows=1 loops=1)
   Buffers: shared hit=266851 read=188773 written=7641
   ->  Hash Join  (cost=101383.08..1142569.79 rows=748148 width=29) (actual time=2427.719..7118.992 rows=773289 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=266851 read=188773 written=7641
         ->  Bitmap Heap Scan on lineitem  (cost=15861.08..1045825.57 rows=748148 width=12) (actual time=669.836..4469.635 rows=773289 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-07-01'::date) AND (l_shipdate < '1993-08-01'::date))
               Heap Blocks: exact=412982
               Buffers: shared hit=257099 read=158000 written=7629
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15674.05 rows=748148 width=0) (actual time=437.849..437.849 rows=774760 loops=1)
                     Index Cond: ((l_shipdate >= '1993-07-01'::date) AND (l_shipdate < '1993-08-01'::date))
                     Buffers: shared read=2117
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1736.323..1736.323 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=9749 read=30773 written=12
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.014..897.358 rows=2000000 loops=1)
                     Buffers: shared hit=9749 read=30773 written=12
 Planning time: 3.049 ms
 Execution time: 7496.010 ms
(19 rows)

COMMIT;
COMMIT