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 = 'STANDARD BRUSHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1738577.27..1738579.10 rows=732 width=38) (actual time=12028.782..12028.783 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=1772858 read=236115 dirtied=402 written=224 -> HashAggregate (cost=1738529.63..1738542.44 rows=732 width=38) (actual time=12028.699..12028.700 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1772855 read=236115 dirtied=402 written=224 -> Hash Join (cost=39454.13..1738036.67 rows=24648 width=38) (actual time=1074.424..11983.149 rows=24182 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1772855 read=236115 dirtied=402 written=224 -> Nested Loop (cost=39452.56..1737572.96 rows=24648 width=16) (actual time=1074.338..11937.741 rows=24182 loops=1) Buffers: shared hit=1772851 read=236115 dirtied=402 written=224 -> Hash Join (cost=39452.27..1729619.97 rows=24648 width=16) (actual time=1074.314..11706.173 rows=24182 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1700184 read=236115 dirtied=402 written=224 -> Nested Loop (cost=421.58..1689880.66 rows=123238 width=20) (actual time=11.017..10527.689 rows=121391 loops=1) Buffers: shared hit=1559853 read=230298 dirtied=402 written=215 -> Nested Loop (cost=421.15..1491417.45 rows=405316 width=16) (actual time=10.823..5188.779 rows=399609 loops=1) Buffers: shared hit=275778 read=192655 dirtied=298 written=173 -> Bitmap Heap Scan on part (cost=416.43..28227.58 rows=13420 width=4) (actual time=10.681..185.632 rows=13305 loops=1) Recheck Cond: ((p_type)::text = 'STANDARD BRUSHED STEEL'::text) Heap Blocks: exact=11426 Buffers: shared hit=2955 read=8554 written=10 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..413.08 rows=13420 width=0) (actual time=7.698..7.698 rows=13305 loops=1) Index Cond: ((p_type)::text = 'STANDARD BRUSHED STEEL'::text) Buffers: shared read=83 written=1 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.046..0.364 rows=30 loops=13305) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=401601 Buffers: shared hit=272823 read=184101 dirtied=298 written=163 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.030..0.030 rows=30 loops=13305) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39923 read=15400 written=9 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.013..0.013 rows=0 loops=399609) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1284075 read=37643 dirtied=104 written=42 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1060.151..1060.151 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=140331 read=5817 written=9 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=31.926..952.282 rows=299493 loops=1) Buffers: shared hit=140331 read=5817 written=9 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.075..0.103 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..0.012 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.035..0.035 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=0.018..0.021 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=23.620..176.487 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=140329 read=5817 written=9 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=15.622..15.622 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=824 written=3 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.008..0.008 rows=1 loops=24182) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72667 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.033..0.033 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=0.005..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 12.701 ms Execution time: 12030.240 ms (70 rows) COMMIT; COMMIT