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 '1997-03-01'
	and l_shipdate < cast(date '1997-03-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1167167.26..1167167.28 rows=1 width=29) (actual time=8118.770..8118.770 rows=1 loops=1)
   Buffers: shared hit=293694 read=161996 written=4746
   ->  Hash Join  (cost=101901.74..1153646.73 rows=772602 width=29) (actual time=2674.616..7736.850 rows=773590 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=293694 read=161996 written=4746
         ->  Bitmap Heap Scan on lineitem  (cost=16379.74..1056535.70 rows=772602 width=12) (actual time=801.469..4539.530 rows=773590 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-03-01'::date) AND (l_shipdate < '1997-04-01'::date))
               Heap Blocks: exact=413047
               Buffers: shared hit=286010 read=129155 written=4746
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16186.59 rows=772602 width=0) (actual time=540.860..540.860 rows=775235 loops=1)
                     Index Cond: ((l_shipdate >= '1997-03-01'::date) AND (l_shipdate < '1997-04-01'::date))
                     Buffers: shared hit=1 read=2117
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1852.910..1852.910 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=7681 read=32841
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.028..975.801 rows=2000000 loops=1)
                     Buffers: shared hit=7681 read=32841
 Planning time: 2.919 ms
 Execution time: 8130.311 ms
(19 rows)

COMMIT;
COMMIT