BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	l_shipmode,
	sum(case
		when o_orderpriority = '1-URGENT'
			or o_orderpriority = '2-HIGH'
			then 1
		else 0
	end) as high_line_count,
	sum(case
		when o_orderpriority <> '1-URGENT'
			and o_orderpriority <> '2-HIGH'
			then 1
		else 0
	end) as low_line_count
from
	orders,
	lineitem
where
	o_orderkey = l_orderkey
	and l_shipmode in ('FOB', 'RAIL')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1993-01-01'
	and l_receiptdate < date '1993-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                          
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=994677.44..994677.44 rows=1 width=27) (actual time=34327.711..34327.711 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=869707 read=497659 written=27
   ->  HashAggregate  (cost=994677.42..994677.43 rows=1 width=27) (actual time=34327.581..34327.582 rows=2 loops=1)
         Buffers: shared hit=869702 read=497659 written=27
         ->  Hash Join  (cost=599625.78..989507.50 rows=295424 width=27) (actual time=15411.619..33770.019 rows=312829 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=869702 read=497659 written=27
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..380649.72 rows=295424 width=15) (actual time=0.381..17162.525 rows=312829 loops=1)
                     Filter: ((l_shipmode = ANY ('{FOB,RAIL}'::bpchar[])) AND (l_receiptdate >= '1993-01-01'::date) AND (l_receiptdate < '1994-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6883896
                     Buffers: shared hit=615348 read=494944 written=27
               ->  Hash  (cost=409314.79..409314.79 rows=15224879 width=20) (actual time=15395.749..15395.749 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 762481kB
                     Buffers: shared hit=254351 read=2715
                     ->  Seq Scan on orders  (cost=0.00..409314.79 rows=15224879 width=20) (actual time=0.017..7473.585 rows=15015000 loops=1)
                           Buffers: shared hit=254351 read=2715
 Total runtime: 34432.186 ms
(19 rows)

COMMIT;
COMMIT