BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ROMANIA' 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 = 'STANDARD POLISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2213906.62..2213908.45 rows=732 width=38) (actual time=64080.355..64080.355 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=742736 read=264810 dirtied=549 written=810 -> HashAggregate (cost=2213858.99..2213871.80 rows=732 width=38) (actual time=64080.292..64080.294 rows=2 loops=1) Buffers: shared hit=742733 read=264810 dirtied=549 written=810 -> Nested Loop (cost=497163.28..2213356.19 rows=25140 width=38) (actual time=34229.675..63947.389 rows=24472 loops=1) Buffers: shared hit=742733 read=264810 dirtied=549 written=810 -> Nested Loop (cost=497163.28..2206186.26 rows=25140 width=16) (actual time=34229.602..62237.209 rows=24472 loops=1) Buffers: shared hit=693789 read=264810 dirtied=549 written=810 -> Hash Join (cost=497163.28..2198864.26 rows=25144 width=16) (actual time=34229.553..60328.759 rows=24472 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=620250 read=264810 dirtied=549 written=810 -> Nested Loop (cost=0.00..1699380.91 rows=413724 width=16) (actual time=0.703..24798.252 rows=402162 loops=1) Buffers: shared hit=225781 read=245931 dirtied=548 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47471.78 rows=13713 width=4) (actual time=0.300..825.866 rows=13387 loops=1) Index Cond: (p_type = 'STANDARD POLISHED NICKEL'::text) Heap Fetches: 13387 Buffers: shared hit=2325 read=9212 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.15 rows=31 width=20) (actual time=0.196..1.771 rows=30 loops=13387) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=223456 read=236719 dirtied=548 -> Hash (cost=485710.98..485710.98 rows=916184 width=8) (actual time=34227.574..34227.574 rows=912880 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35660kB Buffers: shared hit=394466 read=18879 dirtied=1 written=810 -> Hash Join (cost=136122.93..485710.98 rows=916184 width=8) (actual time=8935.829..33584.675 rows=912880 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=394466 read=18879 dirtied=1 written=810 -> Bitmap Heap Scan on orders (cost=97092.31..420340.08 rows=4580918 width=12) (actual time=4313.878..15638.732 rows=4557142 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=259343 read=7825 dirtied=1 written=281 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95947.08 rows=4580918 width=0) (actual time=4182.169..4182.169 rows=4584480 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=7219 read=5415 written=237 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=4621.682..4621.682 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=135123 read=11054 written=529 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=51.770..4405.531 rows=300963 loops=1) Buffers: shared hit=135123 read=11054 written=529 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.062..0.118 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..0.022 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.033..0.033 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=0.028..0.029 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=50.543..859.215 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=135121 read=11054 written=529 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=39.086..39.086 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=831 written=34 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.074..0.074 rows=1 loops=24472) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73539 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.064..0.065 rows=1 loops=24472) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48944 Total runtime: 64089.390 ms (64 rows) COMMIT; COMMIT