BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CANADA' 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 = 'ECONOMY POLISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2138177.38..2138179.20 rows=728 width=38) (actual time=36079.420..36079.420 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=771111 read=231038 dirtied=2034 written=93 -> HashAggregate (cost=2138130.03..2138142.77 rows=728 width=38) (actual time=36079.333..36079.334 rows=2 loops=1) Buffers: shared hit=771108 read=231038 dirtied=2034 written=93 -> Nested Loop (cost=500184.70..2137655.41 rows=23731 width=38) (actual time=25863.288..36006.843 rows=24168 loops=1) Buffers: shared hit=771108 read=231038 dirtied=2034 written=93 -> Nested Loop (cost=500184.70..2130887.33 rows=23731 width=16) (actual time=25863.209..35788.499 rows=24168 loops=1) Buffers: shared hit=722772 read=231038 dirtied=2034 written=93 -> Hash Join (cost=500184.70..2123974.48 rows=23739 width=16) (actual time=25863.152..35297.116 rows=24168 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=650136 read=231038 dirtied=2034 written=93 -> Nested Loop (cost=0.00..1621588.39 rows=392801 width=16) (actual time=0.428..8331.918 rows=396631 loops=1) Buffers: shared hit=249645 read=216908 dirtied=2034 written=81 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45283.37 rows=12980 width=4) (actual time=0.363..343.372 rows=13206 loops=1) Index Cond: (p_type = 'ECONOMY POLISHED STEEL'::text) Heap Fetches: 13206 Buffers: shared read=11406 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.13 rows=31 width=20) (actual time=0.060..0.589 rows=30 loops=13206) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=249645 read=205502 dirtied=2034 written=79 -> Hash (cost=488751.26..488751.26 rows=914675 width=8) (actual time=25860.881..25860.881 rows=910345 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35561kB Buffers: shared hit=400488 read=14130 written=12 -> Hash Join (cost=138305.71..488751.26 rows=914675 width=8) (actual time=5865.145..25267.470 rows=910345 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=400488 read=14130 written=12 -> Bitmap Heap Scan on orders (cost=99275.09..423423.73 rows=4573376 width=12) (actual time=3682.053..10607.919 rows=4557063 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=255377 read=13303 written=12 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98131.74 rows=4573376 width=0) (actual time=3572.059..3572.059 rows=4598186 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=2 read=13130 written=9 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=2182.855..2182.855 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10528kB Buffers: shared hit=145111 read=827 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=76.232..1980.776 rows=299436 loops=1) Buffers: shared hit=145111 read=827 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.026..0.093 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=0.004..0.019 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.013..0.013 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 = 'AMERICA'::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=45.613..376.310 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145109 read=827 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=34.789..34.789 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=827 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.018..0.018 rows=1 loops=24168) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72636 -> 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=24168) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48336 Total runtime: 36087.894 ms (64 rows) COMMIT; COMMIT