BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'PERU' 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 = 'AMERICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'MEDIUM PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1707992.04..1707993.86 rows=730 width=38) (actual time=10380.211..10380.211 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=1970774 read=312709 dirtied=2565 written=584 -> HashAggregate (cost=1707944.54..1707957.32 rows=730 width=38) (actual time=10380.143..10380.145 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1970771 read=312709 dirtied=2565 written=584 -> Hash Join (cost=39439.49..1707464.08 rows=24023 width=38) (actual time=1070.339..10341.740 rows=24094 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1970771 read=312709 dirtied=2565 written=584 -> Nested Loop (cost=39437.93..1707012.09 rows=24023 width=16) (actual time=1070.280..10308.284 rows=24094 loops=1) Buffers: shared hit=1970767 read=312709 dirtied=2565 written=584 -> Hash Join (cost=39437.64..1699253.03 rows=24047 width=16) (actual time=1070.253..10122.830 rows=24094 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1898347 read=312709 dirtied=2565 written=584 -> Nested Loop (cost=406.95..1659530.99 rows=120237 width=20) (actual time=6.812..8977.348 rows=121111 loops=1) Buffers: shared hit=1788510 read=276609 dirtied=2565 written=537 -> Nested Loop (cost=406.52..1465221.59 rows=396826 width=16) (actual time=6.746..3660.889 rows=398727 loops=1) Buffers: shared hit=254968 read=213157 dirtied=2337 written=384 -> Bitmap Heap Scan on part (cost=405.95..27832.29 rows=13100 width=4) (actual time=6.672..170.043 rows=13291 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Heap Blocks: exact=11355 Buffers: shared read=11438 written=28 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.68 rows=13100 width=0) (actual time=4.415..4.415 rows=13291 loops=1) Index Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.41 rows=31 width=20) (actual time=0.024..0.253 rows=30 loops=13291) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=254968 read=201719 dirtied=2337 written=356 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.013..0.013 rows=0 loops=398727) 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=1533542 read=63452 dirtied=228 written=153 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1059.159..1059.159 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=109837 read=36100 written=47 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=19.285..950.186 rows=299436 loops=1) Buffers: shared hit=109837 read=36100 written=47 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.038..0.077 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..0.014 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.015..0.015 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=0.010..0.011 rows=1 loops=1) Filter: (r_name = 'AMERICA'::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=19.590..178.810 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=109835 read=36100 written=47 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.524..12.524 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.007 rows=1 loops=24094) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72420 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.016..0.016 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=0.003..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.988 ms Execution time: 10380.824 ms (68 rows) COMMIT; COMMIT