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 PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1694018.51..1694020.33 rows=728 width=38) (actual time=9106.659..9106.659 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=2060832 read=220252 -> HashAggregate (cost=1693971.16..1693983.90 rows=728 width=38) (actual time=9106.600..9106.601 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2060829 read=220252 -> Hash Join (cost=39434.77..1693498.78 rows=23619 width=38) (actual time=739.580..9073.576 rows=24121 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2060829 read=220252 -> Nested Loop (cost=39433.21..1693054.36 rows=23619 width=16) (actual time=739.508..9044.952 rows=24121 loops=1) Buffers: shared hit=2060825 read=220252 -> Hash Join (cost=39432.92..1685433.37 rows=23619 width=16) (actual time=739.456..8847.952 rows=24121 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1990772 read=217804 -> Nested Loop (cost=402.23..1645723.64 rows=118095 width=20) (actual time=7.994..8029.365 rows=121091 loops=1) Buffers: shared hit=1845661 read=216978 -> Nested Loop (cost=401.80..1454518.57 rows=390506 width=16) (actual time=7.910..3312.246 rows=398771 loops=1) Buffers: shared hit=305890 read=159565 -> Bitmap Heap Scan on part (cost=401.23..27713.96 rows=13007 width=4) (actual time=7.862..169.199 rows=13291 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Heap Blocks: exact=11355 Buffers: shared hit=4 read=11434 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..397.98 rows=13007 width=0) (actual time=5.481..5.481 rows=13291 loops=1) Index Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.39 rows=31 width=20) (actual time=0.024..0.227 rows=30 loops=13291) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=305886 read=148131 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.011..0.011 rows=0 loops=398771) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1539771 read=57413 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=725.657..725.657 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=145111 read=826 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.567..626.762 rows=299436 loops=1) Buffers: shared hit=145111 read=826 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.030..0.079 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..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.012..0.012 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=0.007..0.008 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=18.395..115.117 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=145109 read=826 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.356..12.356 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> 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=24121) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=70053 read=2448 -> 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=0.004..0.011 rows=25 loops=1) Buffers: shared hit=1 Planning time: 10.311 ms Execution time: 9107.372 ms (68 rows) COMMIT; COMMIT