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 = 'LARGE ANODIZED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1698876.72..1698878.55 rows=732 width=38) (actual time=10218.673..10218.673 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=1766029 read=260109 dirtied=1411 written=263 -> HashAggregate (cost=1698829.09..1698841.90 rows=732 width=38) (actual time=10218.615..10218.617 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1766026 read=260109 dirtied=1411 written=263 -> Hash Join (cost=39434.82..1698349.19 rows=23995 width=38) (actual time=1109.351..10175.223 rows=24388 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1766026 read=260109 dirtied=1411 written=263 -> Nested Loop (cost=39433.26..1697897.72 rows=23995 width=16) (actual time=1109.280..10136.677 rows=24388 loops=1) Buffers: shared hit=1766022 read=260109 dirtied=1411 written=263 -> Hash Join (cost=39432.96..1690155.44 rows=23995 width=16) (actual time=1109.263..9939.323 rows=24388 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1692730 read=260109 dirtied=1411 written=263 -> Nested Loop (cost=402.28..1650434.90 rows=119975 width=20) (actual time=7.388..8753.349 rows=122313 loops=1) Buffers: shared hit=1582684 read=224007 dirtied=1411 written=228 -> Nested Loop (cost=401.84..1457221.38 rows=394586 width=16) (actual time=7.272..4191.340 rows=403341 loops=1) Buffers: shared hit=291826 read=181123 dirtied=1378 written=191 -> Bitmap Heap Scan on part (cost=401.28..27720.62 rows=13013 width=4) (actual time=7.181..173.437 rows=13407 loops=1) Recheck Cond: ((p_type)::text = 'LARGE ANODIZED TIN'::text) Heap Blocks: exact=11478 Buffers: shared hit=2137 read=9410 written=12 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..398.02 rows=13013 width=0) (actual time=4.812..4.812 rows=13407 loops=1) Index Cond: ((p_type)::text = 'LARGE ANODIZED TIN'::text) Buffers: shared read=69 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.54 rows=31 width=20) (actual time=0.028..0.288 rows=30 loops=13407) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=289689 read=171713 dirtied=1378 written=179 -> 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=403341) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1290858 read=42884 dirtied=33 written=37 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1097.102..1097.102 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110046 read=36102 written=35 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=22.223..998.843 rows=299493 loops=1) Buffers: shared hit=110046 read=36102 written=35 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.048..0.084 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=0.008..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.019..0.019 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=0.012..0.013 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=19.833..187.957 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110044 read=36102 written=35 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.894..12.894 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 written=3 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.007 rows=1 loops=24388) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73292 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.027..0.027 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=0.005..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.937 ms Execution time: 10219.477 ms (66 rows) COMMIT; COMMIT