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=2191293.01..2191294.84 rows=731 width=38) (actual time=31655.644..31655.645 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=692541 read=311593 dirtied=1016 written=749 -> HashAggregate (cost=2191245.44..2191258.24 rows=731 width=38) (actual time=31655.571..31655.572 rows=2 loops=1) Buffers: shared hit=692538 read=311593 dirtied=1016 written=749 -> Nested Loop (cost=496502.98..2190750.98 rows=24723 width=38) (actual time=22834.989..31582.691 rows=24370 loops=1) Buffers: shared hit=692538 read=311593 dirtied=1016 written=749 -> Nested Loop (cost=496502.98..2183699.98 rows=24723 width=16) (actual time=22834.919..31376.808 rows=24370 loops=1) Buffers: shared hit=643798 read=311593 dirtied=1016 written=749 -> Hash Join (cost=496502.98..2176500.57 rows=24723 width=16) (actual time=22834.872..31000.232 rows=24370 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=570545 read=311593 dirtied=1016 written=749 -> Nested Loop (cost=0.00..1677715.25 rows=407022 width=16) (actual time=0.480..6944.737 rows=400125 loops=1) Buffers: shared hit=208797 read=260362 dirtied=763 written=39 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46876.47 rows=13513 width=4) (actual time=0.399..92.214 rows=13365 loops=1) Index Cond: (p_type = 'SMALL PLATED TIN'::text) Heap Fetches: 13365 Buffers: shared hit=11429 read=71 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.38 rows=31 width=20) (actual time=0.048..0.496 rows=30 loops=13365) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=197368 read=260291 dirtied=763 written=39 -> Hash (cost=485068.54..485068.54 rows=914755 width=8) (actual time=22833.168..22833.168 rows=912424 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35642kB Buffers: shared hit=361745 read=51231 dirtied=253 written=710 -> Hash Join (cost=135881.71..485068.54 rows=914755 width=8) (actual time=5132.715..21899.139 rows=912424 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=361745 read=51231 dirtied=253 written=710 -> Bitmap Heap Scan on orders (cost=96851.09..419738.71 rows=4573775 width=12) (actual time=3270.348..8497.603 rows=4557174 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=251612 read=15126 dirtied=253 written=708 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95707.65 rows=4573775 width=0) (actual time=3154.166..3154.166 rows=4575464 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12457 written=569 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1861.934..1861.934 rows=300270 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10557kB Buffers: shared hit=110133 read=36105 written=2 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=47.437..1697.678 rows=300270 loops=1) Buffers: shared hit=110133 read=36105 written=2 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.081..0.134 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..0.019 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.049..0.049 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=0.043..0.045 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=29.736..322.723 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110131 read=36105 written=2 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=19.723..19.723 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=5 read=831 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.013..0.013 rows=1 loops=24370) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73253 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.005..0.006 rows=1 loops=24370) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48740 Total runtime: 31674.420 ms (64 rows) COMMIT; COMMIT