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 POLISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1746361.63..1746363.46 rows=732 width=38) (actual time=12882.951..12882.952 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=1783479 read=219982 dirtied=139 written=45 -> HashAggregate (cost=1746313.99..1746326.80 rows=732 width=38) (actual time=12882.874..12882.876 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1783476 read=219982 dirtied=139 written=45 -> Hash Join (cost=39454.64..1745820.05 rows=24697 width=38) (actual time=991.416..12833.087 rows=24272 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1783476 read=219982 dirtied=139 written=45 -> Nested Loop (cost=39453.08..1745355.42 rows=24697 width=16) (actual time=991.340..12777.377 rows=24272 loops=1) Buffers: shared hit=1783472 read=219982 dirtied=139 written=45 -> Hash Join (cost=39452.79..1737386.61 rows=24697 width=16) (actual time=991.320..12516.182 rows=24272 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1710512 read=219982 dirtied=139 written=45 -> Nested Loop (cost=422.10..1697645.89 rows=123485 width=20) (actual time=10.547..11401.950 rows=120886 loops=1) Buffers: shared hit=1572207 read=212350 dirtied=139 written=45 -> Nested Loop (cost=421.67..1498788.39 rows=406128 width=16) (actual time=9.746..5583.371 rows=398624 loops=1) Buffers: shared hit=283021 read=183379 dirtied=87 written=38 -> Bitmap Heap Scan on part (cost=416.95..28307.28 rows=13487 width=4) (actual time=9.618..229.243 rows=13296 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM POLISHED TIN'::text) Heap Blocks: exact=11397 Buffers: shared hit=810 read=10655 written=3 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..413.58 rows=13487 width=0) (actual time=6.633..6.633 rows=13296 loops=1) Index Cond: ((p_type)::text = 'MEDIUM POLISHED TIN'::text) Buffers: shared read=68 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.049..0.388 rows=30 loops=13296) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=399738 Buffers: shared hit=282211 read=172724 dirtied=87 written=35 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.033..0.033 rows=30 loops=13296) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39789 read=15408 written=5 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.014..0.014 rows=0 loops=398624) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1289186 read=28971 dirtied=52 written=7 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=977.821..977.821 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=138305 read=7632 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=30.221..883.078 rows=299436 loops=1) Buffers: shared hit=138305 read=7632 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.054..0.086 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..0.014 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.024..0.024 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..0.019 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=21.570..164.166 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=138303 read=7632 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=14.266..14.266 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.009..0.009 rows=1 loops=24272) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72960 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.030..0.030 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=0.006..0.012 rows=25 loops=1) Buffers: shared hit=1 Planning time: 10.934 ms Execution time: 12884.150 ms (70 rows) COMMIT; COMMIT