BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'GERMANY' 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 = 'EUROPE' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'SMALL POLISHED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2149559.85..2149561.67 rows=730 width=38) (actual time=28716.907..28716.908 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=729775 read=265998 dirtied=1109 written=1 -> HashAggregate (cost=2149512.36..2149525.13 rows=730 width=38) (actual time=28716.846..28716.847 rows=2 loops=1) Buffers: shared hit=729772 read=265998 dirtied=1109 written=1 -> Nested Loop (cost=497719.29..2149033.14 rows=23961 width=38) (actual time=21231.462..28654.860 rows=24020 loops=1) Buffers: shared hit=729772 read=265998 dirtied=1109 written=1 -> Nested Loop (cost=497719.29..2142199.46 rows=23961 width=16) (actual time=21231.396..28507.861 rows=24020 loops=1) Buffers: shared hit=681732 read=265998 dirtied=1109 written=1 -> Hash Join (cost=497719.29..2135214.38 rows=23987 width=16) (actual time=21231.355..28209.951 rows=24020 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=609523 read=265998 dirtied=1109 written=1 -> Nested Loop (cost=0.00..1635276.96 rows=395651 width=16) (actual time=0.301..5824.249 rows=394022 loops=1) Buffers: shared hit=212150 read=249770 dirtied=1109 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45681.97 rows=13113 width=4) (actual time=0.247..151.028 rows=13153 loops=1) Index Cond: (p_type = 'SMALL POLISHED COPPER'::text) Heap Fetches: 13153 Buffers: shared hit=8315 read=3020 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.91 rows=31 width=20) (actual time=0.039..0.417 rows=30 loops=13153) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=203835 read=246750 dirtied=1109 -> Hash (cost=486283.49..486283.49 rows=914864 width=8) (actual time=21230.300..21230.300 rows=913799 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35696kB Buffers: shared hit=397370 read=16228 written=1 -> Hash Join (cost=136579.33..486283.49 rows=914864 width=8) (actual time=4519.469..20527.587 rows=913799 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=397370 read=16228 written=1 -> Bitmap Heap Scan on orders (cost=97548.71..420950.53 rows=4574321 width=12) (actual time=3479.790..7498.550 rows=4561664 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=253426 read=13995 written=1 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..96405.13 rows=4574321 width=0) (actual time=3313.350..3313.350 rows=4584480 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12634 written=1 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1039.239..1039.239 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=143944 read=2233 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=20.981..900.283 rows=300963 loops=1) Buffers: shared hit=143944 read=2233 -> 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=0.007..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.013..0.013 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 1kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.008..0.010 rows=1 loops=1) Filter: (r_name = 'EUROPE'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=26.000..164.364 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=143942 read=2233 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=17.613..17.613 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=832 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.010..0.010 rows=1 loops=24020) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72209 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.004 rows=1 loops=24020) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48040 Total runtime: 28732.224 ms (64 rows) COMMIT; COMMIT