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 = 'MEDIUM POLISHED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2198938.18..2198940.00 rows=728 width=38) (actual time=32944.497..32944.498 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=843110 read=161125 dirtied=558 written=6319 -> HashAggregate (cost=2198890.83..2198903.57 rows=728 width=38) (actual time=32944.429..32944.431 rows=2 loops=1) Buffers: shared hit=843107 read=161125 dirtied=558 written=6319 -> Nested Loop (cost=494263.98..2198397.01 rows=24691 width=38) (actual time=25551.944..32875.475 rows=24504 loops=1) Buffers: shared hit=843107 read=161125 dirtied=558 written=6319 -> Nested Loop (cost=494263.98..2191355.14 rows=24691 width=16) (actual time=25551.872..32686.252 rows=24504 loops=1) Buffers: shared hit=794099 read=161125 dirtied=558 written=6319 -> Hash Join (cost=494263.98..2184162.41 rows=24700 width=16) (actual time=25551.828..32270.276 rows=24504 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=720482 read=161121 dirtied=558 written=6319 -> Nested Loop (cost=0.00..1687607.94 rows=408699 width=16) (actual time=0.300..5263.674 rows=401434 loops=1) Buffers: shared hit=376063 read=93321 dirtied=558 written=3889 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47178.43 rows=13613 width=4) (actual time=0.239..253.251 rows=13402 loops=1) Index Cond: (p_type = 'MEDIUM POLISHED COPPER'::text) Heap Fetches: 13402 Buffers: shared hit=3161 read=8384 written=292 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.19 rows=31 width=20) (actual time=0.045..0.358 rows=30 loops=13402) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=372902 read=84937 dirtied=558 written=3597 -> Hash (cost=482921.18..482921.18 rows=907424 width=8) (actual time=25549.138..25549.138 rows=912402 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35641kB Buffers: shared hit=344416 read=67800 written=2430 -> Hash Join (cost=135253.98..482921.18 rows=907424 width=8) (actual time=5123.058..23909.052 rows=912402 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=344416 read=67800 written=2430 -> Bitmap Heap Scan on orders (cost=96223.35..417802.12 rows=4537118 width=12) (actual time=2839.989..9098.770 rows=4557440 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=210167 read=55811 written=2430 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95089.08 rows=4537118 width=0) (actual time=2699.843..2699.843 rows=4561961 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=10507 read=1949 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=2282.741..2282.741 rows=300270 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10557kB Buffers: shared hit=134249 read=11989 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=71.720..2066.960 rows=300270 loops=1) Buffers: shared hit=134249 read=11989 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.029..0.102 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=0.005..0.021 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.014..0.014 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 1kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.011..0.012 rows=1 loops=1) Filter: (r_name = 'ASIA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=43.352..392.761 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=134247 read=11989 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=31.508..31.508 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=12 read=824 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.014..0.015 rows=1 loops=24504) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73617 read=4 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=24504) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49008 Total runtime: 32961.171 ms (64 rows) COMMIT; COMMIT