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 '1996-12-01'
	and l_shipdate < cast(date '1996-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1172016.48..1172016.50 rows=1 width=29) (actual time=8529.239..8529.239 rows=1 loops=1)
   Buffers: shared hit=201015 read=257871 written=181
   ->  Hash Join  (cost=101794.65..1158528.53 rows=770740 width=29) (actual time=2781.960..8103.648 rows=773334 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=201015 read=257871 written=181
         ->  Bitmap Heap Scan on lineitem  (cost=16272.65..1061445.43 rows=770740 width=12) (actual time=941.003..5439.732 rows=773334 loops=1)
               Recheck Cond: ((l_shipdate >= '1996-12-01'::date) AND (l_shipdate < '1997-01-01'::date))
               Heap Blocks: exact=416245
               Buffers: shared hit=200277 read=218084 written=145
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16079.97 rows=770740 width=0) (actual time=607.310..607.310 rows=780256 loops=1)
                     Index Cond: ((l_shipdate >= '1996-12-01'::date) AND (l_shipdate < '1997-01-01'::date))
                     Buffers: shared read=2116 written=2
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1828.338..1828.338 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=735 read=39787 written=36
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.012..1057.174 rows=2000000 loops=1)
                     Buffers: shared hit=735 read=39787 written=36
 Planning time: 4.928 ms
 Execution time: 8535.991 ms
(19 rows)

COMMIT;
COMMIT