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 ('AIR', 'TRUCK')
	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=986175.85..986175.85 rows=1 width=27) (actual time=68599.748..68599.748 rows=2 loops=1)
   Sort Key: lineitem.l_shipmode
   Sort Method: quicksort  Memory: 25kB
   Buffers: shared hit=1160097 read=207698 written=79
   ->  HashAggregate  (cost=986175.83..986175.84 rows=1 width=27) (actual time=68599.593..68599.595 rows=2 loops=1)
         Buffers: shared hit=1160092 read=207698 written=79
         ->  Hash Join  (cost=594902.33..981043.18 rows=293294 width=27) (actual time=25047.019..67903.333 rows=312786 loops=1)
               Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
               Buffers: shared hit=1160092 read=207698 written=79
               ->  Index Scan using lineitem_l_orderkey_idx_part2 on lineitem  (cost=0.00..376975.42 rows=293294 width=15) (actual time=0.310..41332.441 rows=312786 loops=1)
                     Filter: ((l_shipmode = ANY ('{AIR,TRUCK}'::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: 6883983
                     Buffers: shared hit=905048 read=207698 written=79
               ->  Hash  (cost=406090.48..406090.48 rows=15104948 width=20) (actual time=25038.461..25038.461 rows=15015000 loops=1)
                     Buckets: 2097152  Batches: 1  Memory Usage: 762481kB
                     Buffers: shared hit=255041
                     ->  Seq Scan on orders  (cost=0.00..406090.48 rows=15104948 width=20) (actual time=0.022..14946.886 rows=15015000 loops=1)
                           Buffers: shared hit=255041
 Total runtime: 68738.181 ms
(19 rows)

COMMIT;
COMMIT