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 '1993-12-01'
	and l_shipdate < cast(date '1993-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1174162.84..1174162.86 rows=1 width=29) (actual time=10178.608..10178.608 rows=1 loops=1)
   Buffers: shared hit=199774 read=259137 written=262
   ->  Hash Join  (cost=101810.37..1160648.05 rows=772274 width=29) (actual time=3111.993..9639.958 rows=772987 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=199774 read=259137 written=262
         ->  Bitmap Heap Scan on lineitem  (cost=16288.37..1063541.94 rows=772274 width=12) (actual time=680.668..6217.617 rows=772987 loops=1)
               Recheck Cond: ((l_shipdate >= '1993-12-01'::date) AND (l_shipdate < '1994-01-01'::date))
               Heap Blocks: exact=416273
               Buffers: shared hit=186070 read=232316 written=220
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16095.31 rows=772274 width=0) (actual time=444.256..444.256 rows=781326 loops=1)
                     Index Cond: ((l_shipdate >= '1993-12-01'::date) AND (l_shipdate < '1994-01-01'::date))
                     Buffers: shared read=2113 written=5
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=2418.502..2418.502 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=13701 read=26821 written=42
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.015..1384.534 rows=2000000 loops=1)
                     Buffers: shared hit=13701 read=26821 written=42
 Planning time: 3.200 ms
 Execution time: 10184.937 ms
(19 rows)

COMMIT;
COMMIT