BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 = 'AFRICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'ECONOMY ANODIZED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1701516.59..1701518.41 rows=729 width=38) (actual time=8122.422..8122.422 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=1811682 read=214888 dirtied=1823 -> HashAggregate (cost=1701469.17..1701481.92 rows=729 width=38) (actual time=8122.333..8122.335 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1811679 read=214888 dirtied=1823 -> Hash Join (cost=39439.18..1700992.89 rows=23814 width=38) (actual time=683.515..8087.439 rows=24409 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1811679 read=214888 dirtied=1823 -> Nested Loop (cost=39437.62..1700544.81 rows=23814 width=16) (actual time=683.426..8057.565 rows=24409 loops=1) Buffers: shared hit=1811675 read=214888 dirtied=1823 -> Hash Join (cost=39437.33..1692854.79 rows=23833 width=16) (actual time=683.406..7889.884 rows=24409 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1738329 read=214888 dirtied=1823 -> Nested Loop (cost=406.64..1653138.90 rows=119165 width=20) (actual time=9.514..7142.448 rows=122382 loops=1) Buffers: shared hit=1593006 read=214063 dirtied=1823 -> Nested Loop (cost=406.21..1460383.31 rows=393664 width=16) (actual time=9.288..3482.104 rows=403449 loops=1) Buffers: shared hit=293626 read=179278 dirtied=1823 -> Bitmap Heap Scan on part (cost=405.64..27782.65 rows=13060 width=4) (actual time=9.243..172.423 rows=13452 loops=1) Recheck Cond: ((p_type)::text = 'ECONOMY ANODIZED STEEL'::text) Heap Blocks: exact=11517 Buffers: shared hit=1 read=11601 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.38 rows=13060 width=0) (actual time=7.200..7.200 rows=13452 loops=1) Index Cond: ((p_type)::text = 'ECONOMY ANODIZED STEEL'::text) Buffers: shared read=85 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.38 rows=31 width=20) (actual time=0.024..0.237 rows=30 loops=13452) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=293625 read=167677 dirtied=1823 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.008..0.009 rows=0 loops=403449) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1299380 read=34785 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=669.843..669.843 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=145323 read=825 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=17.658..580.567 rows=299493 loops=1) Buffers: shared hit=145323 read=825 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.028..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=0.003..0.021 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.011..0.011 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=0.006..0.008 rows=1 loops=1) Filter: (r_name = 'AFRICA'::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=16.247..106.675 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=145321 read=825 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=10.656..10.656 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.006 rows=1 loops=24409) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73346 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.035..0.035 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=0.007..0.014 rows=25 loops=1) Buffers: shared hit=1 Planning time: 12.474 ms Execution time: 8123.299 ms (66 rows) COMMIT; COMMIT