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 '1993-04-01'
	and l_shipdate < cast(date '1993-04-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1163311.45..1163311.46 rows=1 width=29) (actual time=7662.102..7662.102 rows=1 loops=1)
   Buffers: shared hit=196120 read=254463 written=297
   ->  Hash Join  (cost=101523.64..1150067.66 rows=756788 width=29) (actual time=2189.526..7272.772 rows=749776 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=196120 read=254463 written=297
         ->  Bitmap Heap Scan on lineitem  (cost=16001.64..1053193.84 rows=756788 width=12) (actual time=675.514..4943.239 rows=749776 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
               Heap Blocks: exact=408007
               Buffers: shared hit=157978 read=252080 written=295
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..15812.45 rows=756788 width=0) (actual time=441.825..441.825 rows=754251 loops=1)
                     Index Cond: ((l_shipdate >= '1993-04-01'::date) AND (l_shipdate < '1993-05-01'::date))
                     Buffers: shared hit=3 read=2048 written=6
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1501.827..1501.827 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=38139 read=2383 written=2
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.013..693.009 rows=2000000 loops=1)
                     Buffers: shared hit=38139 read=2383 written=2
 Planning time: 3.259 ms
 Execution time: 7665.006 ms
(19 rows)

COMMIT;
COMMIT