BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ALGERIA' 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 = 'AFRICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'PROMO BRUSHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2131775.49..2131777.32 rows=733 width=38) (actual time=25677.572..25677.572 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=716009 read=289137 dirtied=982 written=1 -> HashAggregate (cost=2131727.78..2131740.61 rows=733 width=38) (actual time=25677.508..25677.510 rows=2 loops=1) Buffers: shared hit=716006 read=289137 dirtied=982 written=1 -> Nested Loop (cost=497000.39..2131253.06 rows=23736 width=38) (actual time=19834.891..25628.825 rows=24709 loops=1) Buffers: shared hit=716006 read=289137 dirtied=982 written=1 -> Nested Loop (cost=497000.39..2124483.55 rows=23736 width=16) (actual time=19834.814..25521.145 rows=24709 loops=1) Buffers: shared hit=666588 read=289137 dirtied=982 written=1 -> Hash Join (cost=497000.39..2117563.69 rows=23763 width=16) (actual time=19834.774..25282.621 rows=24709 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=592327 read=289137 dirtied=982 written=1 -> Nested Loop (cost=0.00..1618374.36 rows=390262 width=16) (actual time=0.293..4364.679 rows=400459 loops=1) Buffers: shared hit=280114 read=188460 dirtied=982 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45222.59 rows=12960 width=4) (actual time=0.226..117.439 rows=13351 loops=1) Index Cond: (p_type = 'PROMO BRUSHED STEEL'::text) Heap Fetches: 13351 Buffers: shared hit=6295 read=5184 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.08 rows=31 width=20) (actual time=0.031..0.307 rows=30 loops=13351) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=273819 read=183276 dirtied=982 -> Hash (cost=485538.09..485538.09 rows=916984 width=8) (actual time=19833.684..19833.684 rows=911910 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=312210 read=100677 written=1 -> Hash Join (cost=136119.97..485538.09 rows=916984 width=8) (actual time=3756.792..19016.996 rows=911910 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=312210 read=100677 written=1 -> Bitmap Heap Scan on orders (cost=97089.35..420144.18 rows=4584922 width=12) (actual time=2779.132..6681.483 rows=4561773 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=174249 read=92489 written=1 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95943.12 rows=4584922 width=0) (actual time=2640.850..2640.850 rows=4575464 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12457 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=977.236..977.236 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=137961 read=8188 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=19.790..853.647 rows=299493 loops=1) Buffers: shared hit=137961 read=8188 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.027..0.083 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=0.009..0.011 rows=1 loops=1) Filter: (r_name = 'AFRICA'::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=23.365..157.046 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=137959 read=8188 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=15.650..15.650 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.008..0.008 rows=1 loops=24709) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=74261 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.003 rows=1 loops=24709) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49418 Total runtime: 25689.599 ms (64 rows) COMMIT; COMMIT