BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'BRAZIL' 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=1709074.32..1709076.13 rows=727 width=38) (actual time=9854.260..9854.261 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=1782030 read=220158 dirtied=350 written=2567 -> HashAggregate (cost=1709027.04..1709039.76 rows=727 width=38) (actual time=9854.194..9854.195 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1782027 read=220158 dirtied=350 written=2567 -> Hash Join (cost=39439.75..1708549.10 rows=23897 width=38) (actual time=828.469..9815.454 rows=24258 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1782027 read=220158 dirtied=350 written=2567 -> Nested Loop (cost=39438.19..1708099.47 rows=23897 width=16) (actual time=828.411..9780.484 rows=24258 loops=1) Buffers: shared hit=1782023 read=220158 dirtied=350 written=2567 -> Hash Join (cost=39437.89..1700388.47 rows=23898 width=16) (actual time=828.393..9577.206 rows=24258 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1709105 read=220158 dirtied=350 written=2567 -> Nested Loop (cost=407.21..1660670.72 rows=119489 width=20) (actual time=7.114..8674.135 rows=120777 loops=1) Buffers: shared hit=1564115 read=219211 dirtied=350 written=2527 -> Nested Loop (cost=406.77..1467037.73 rows=395470 width=16) (actual time=6.992..4130.140 rows=398234 loops=1) Buffers: shared hit=275667 read=190781 dirtied=350 written=2315 -> Bitmap Heap Scan on part (cost=406.21..27871.95 rows=13133 width=4) (actual time=6.912..155.657 rows=13296 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM POLISHED TIN'::text) Heap Blocks: exact=11397 Buffers: shared hit=3314 read=8151 written=101 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.93 rows=13133 width=0) (actual time=4.615..4.615 rows=13296 loops=1) Index Cond: ((p_type)::text = 'MEDIUM POLISHED TIN'::text) Buffers: shared read=68 written=4 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.27 rows=31 width=20) (actual time=0.027..0.288 rows=30 loops=13296) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=272353 read=182630 dirtied=350 written=2214 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.011..0.011 rows=0 loops=398234) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1288448 read=28430 written=212 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=817.262..817.262 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=144990 read=947 written=40 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.634..728.211 rows=299436 loops=1) Buffers: shared hit=144990 read=947 written=40 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.057..0.090 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..0.013 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.020..0.020 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=0.013..0.014 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=19.208..135.191 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=144988 read=947 written=40 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.603..12.603 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 written=37 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.007..0.007 rows=1 loops=24258) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72918 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.021..0.021 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=0.004..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.565 ms Execution time: 9855.310 ms (66 rows) COMMIT; COMMIT