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 ('MAIL', 'RAIL')
	and l_commitdate < l_receiptdate
	and l_shipdate < l_commitdate
	and l_receiptdate >= date '1994-01-01'
	and l_receiptdate < date '1994-01-01' + interval '1 year'
group by
	l_shipmode
order by
	l_shipmode;
                                                                                          QUERY PLAN                                                                                           
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Sort  (cost=990711.52..990711.53 rows=1 width=27) (actual time=41661.144..41661.144 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=673278 read=692482 written=275
   ->  HashAggregate  (cost=990711.50..990711.51 rows=1 width=27) (actual time=41661.016..41661.017 rows=2 loops=1)
         Buffers: shared hit=673273 read=692482 written=275
         ->  Hash Join  (cost=597265.22..985570.65 rows=293763 width=27) (actual time=17402.974..41038.802 rows=311283 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=673273 read=692482 written=275
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..379125.34 rows=293763 width=15) (actual time=0.143..22185.260 rows=311283 loops=1)
                     Filter: ((l_shipmode = ANY ('{MAIL,RAIL}'::bpchar[])) AND (l_receiptdate >= '1994-01-01'::date) AND (l_receiptdate < '1995-01-01 00:00:00'::timestamp without time zone))
                     Rows Removed by Filter: 6885299
                     Buffers: shared hit=435750 read=673948 written=269
               ->  Hash  (cost=407703.43..407703.43 rows=15164943 width=20) (actual time=17390.048..17390.048 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 762481kB
                     Buffers: shared hit=237520 read=18534 written=6
                     ->  Seq Scan on orders  (cost=0.00..407703.43 rows=15164943 width=20) (actual time=0.032..7527.472 rows=15015000 loops=1)
                           Buffers: shared hit=237520 read=18534 written=6
 Total runtime: 41803.828 ms
(19 rows)

COMMIT;
COMMIT