BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'JAPAN' then volume else 0 end) / sum(volume) as mkt_share from ( select extract(year from o_orderdate) as o_year, l_extendedprice * (1 - l_discount) as volume, n2.n_name as nation from part, supplier, lineitem, orders, customer, nation n1, nation n2, region where p_partkey = l_partkey and s_suppkey = l_suppkey and l_orderkey = o_orderkey and o_custkey = c_custkey and c_nationkey = n1.n_nationkey and n1.n_regionkey = r_regionkey and r_name = 'ASIA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'SMALL PLATED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1714391.29..1714393.12 rows=729 width=38) (actual time=14994.420..14994.420 rows=2 loops=1) Sort Key: (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone)) Sort Method: quicksort Memory: 25kB Buffers: shared hit=1902143 read=387438 dirtied=369 written=9065 -> HashAggregate (cost=1714343.87..1714356.63 rows=729 width=38) (actual time=14994.360..14994.363 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1902140 read=387438 dirtied=369 written=9065 -> Hash Join (cost=39440.21..1713864.35 rows=23976 width=38) (actual time=1559.222..14944.250 rows=24361 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1902140 read=387438 dirtied=369 written=9065 -> Nested Loop (cost=39438.65..1713413.24 rows=23976 width=16) (actual time=1559.146..14895.651 rows=24361 loops=1) Buffers: shared hit=1902136 read=387438 dirtied=369 written=9065 -> Hash Join (cost=39438.36..1705677.06 rows=23976 width=16) (actual time=1559.104..14679.211 rows=24361 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1829004 read=387344 dirtied=369 written=9065 -> Nested Loop (cost=407.67..1665957.07 rows=119878 width=20) (actual time=7.497..12991.181 rows=121602 loops=1) Buffers: shared hit=1695714 read=374397 dirtied=369 written=9065 -> Nested Loop (cost=407.24..1472016.96 rows=396092 width=16) (actual time=7.292..5410.060 rows=400089 loops=1) Buffers: shared hit=231828 read=235845 dirtied=369 written=5684 -> Bitmap Heap Scan on part (cost=406.67..27946.11 rows=13193 width=4) (actual time=7.210..96.317 rows=13365 loops=1) Recheck Cond: ((p_type)::text = 'SMALL PLATED TIN'::text) Heap Blocks: exact=11430 Buffers: shared hit=9655 read=1844 written=73 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..403.38 rows=13193 width=0) (actual time=4.700..4.700 rows=13365 loops=1) Index Cond: ((p_type)::text = 'SMALL PLATED TIN'::text) Buffers: shared hit=1 read=68 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.15 rows=31 width=20) (actual time=0.034..0.386 rows=30 loops=13365) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=222173 read=234001 dirtied=369 written=5611 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.018..0.018 rows=0 loops=400089) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1463886 read=138552 written=3381 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1548.919..1548.919 rows=300270 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14653kB Buffers: shared hit=133290 read=12947 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=23.877..1383.759 rows=300270 loops=1) Buffers: shared hit=133290 read=12947 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.046..0.097 rows=5 loops=1) Hash Cond: (n1.n_regionkey = region.r_regionkey) Buffers: shared hit=2 -> Seq Scan on nation n1 (cost=0.00..1.25 rows=25 width=8) (actual time=0.007..0.018 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.018..0.018 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.013..0.014 rows=1 loops=1) Filter: (r_name = 'ASIA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=31.158..259.271 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145400 Buffers: shared hit=133288 read=12947 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=21.939..21.939 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=10 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.007..0.008 rows=1 loops=24361) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73132 read=94 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.019..0.019 rows=25 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 10kB Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.006 rows=25 loops=1) Buffers: shared hit=1 Planning time: 6.980 ms Execution time: 14995.528 ms (68 rows) COMMIT; COMMIT