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 '1994-12-01'
	and l_shipdate < cast(date '1994-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1181603.66..1181603.67 rows=1 width=29) (actual time=7442.017..7442.017 rows=1 loops=1)
   Buffers: shared hit=250294 read=210245 dirtied=428 written=219
   ->  Hash Join  (cost=102112.74..1167832.14 rows=786944 width=29) (actual time=2249.981..7060.422 rows=774264 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=250294 read=210245 dirtied=428 written=219
         ->  Bitmap Heap Scan on lineitem  (cost=16590.74..1070505.98 rows=786944 width=12) (actual time=667.764..4551.141 rows=774264 loops=1)
               Recheck Cond: ((l_shipdate >= '1994-12-01'::date) AND (l_shipdate < '1995-01-01'::date))
               Heap Blocks: exact=417897
               Buffers: shared hit=237040 read=182974 dirtied=428 written=219
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16394.01 rows=786944 width=0) (actual time=432.644..432.644 rows=783497 loops=1)
                     Index Cond: ((l_shipdate >= '1994-12-01'::date) AND (l_shipdate < '1995-01-01'::date))
                     Buffers: shared read=2117
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1570.529..1570.529 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=13251 read=27271
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.013..862.224 rows=2000000 loops=1)
                     Buffers: shared hit=13251 read=27271
 Planning time: 3.096 ms
 Execution time: 7445.192 ms
(19 rows)

COMMIT;
COMMIT