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 = 'PROMO BRUSHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2138159.41..2138161.24 rows=730 width=38) (actual time=28027.963..28027.964 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=705981 read=293225 dirtied=928 written=79 -> HashAggregate (cost=2138111.92..2138124.70 rows=730 width=38) (actual time=28027.856..28027.858 rows=2 loops=1) Buffers: shared hit=705978 read=293225 dirtied=928 written=79 -> Nested Loop (cost=495719.77..2137637.04 rows=23744 width=38) (actual time=21744.890..27976.234 rows=24151 loops=1) Buffers: shared hit=705978 read=293225 dirtied=928 written=79 -> Nested Loop (cost=495719.77..2130865.25 rows=23744 width=16) (actual time=21744.807..27858.775 rows=24151 loops=1) Buffers: shared hit=657676 read=293225 dirtied=928 written=79 -> Hash Join (cost=495719.77..2123943.35 rows=23770 width=16) (actual time=21744.752..27606.757 rows=24151 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=585194 read=293117 dirtied=928 written=79 -> Nested Loop (cost=0.00..1626025.55 rows=392067 width=16) (actual time=0.405..4707.950 rows=398483 loops=1) Buffers: shared hit=275167 read=190719 dirtied=420 written=44 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45444.57 rows=13033 width=4) (actual time=0.329..188.052 rows=13283 loops=1) Index Cond: (p_type = 'PROMO BRUSHED TIN'::text) Heap Fetches: 13283 Buffers: shared hit=392 read=11021 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.97 rows=31 width=20) (actual time=0.033..0.328 rows=30 loops=13283) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=274775 read=179698 dirtied=420 written=42 -> Hash (cost=484318.03..484318.03 rows=912139 width=8) (actual time=21743.336..21743.336 rows=911247 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35596kB Buffers: shared hit=310024 read=102398 dirtied=508 written=35 -> Hash Join (cost=135655.63..484318.03 rows=912139 width=8) (actual time=5221.428..21142.749 rows=911247 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=310024 read=102398 dirtied=508 written=35 -> Bitmap Heap Scan on orders (cost=96625.01..419063.42 rows=4560694 width=12) (actual time=3255.967..7582.009 rows=4561956 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=200187 read=66297 dirtied=508 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95484.84 rows=4560694 width=0) (actual time=3099.673..3099.673 rows=4570988 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12456 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1965.171..1965.171 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10528kB Buffers: shared hit=109837 read=36101 written=35 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=32.111..1759.561 rows=299436 loops=1) Buffers: shared hit=109837 read=36101 written=35 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.043..0.121 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=0.006..0.025 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.023..0.023 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=0.019..0.021 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=33.777..331.078 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=109835 read=36101 written=35 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=23.106..23.106 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=0.009..0.009 rows=1 loops=24151) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72482 read=108 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.003 rows=1 loops=24151) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48302 Total runtime: 28053.360 ms (64 rows) COMMIT; COMMIT