BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'KENYA' 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 = 'ECONOMY POLISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1698539.31..1698541.14 rows=733 width=38) (actual time=8728.305..8728.305 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=1799511 read=227873 dirtied=712 written=30 -> HashAggregate (cost=1698491.60..1698504.42 rows=733 width=38) (actual time=8728.252..8728.252 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1799508 read=227873 dirtied=712 written=30 -> Hash Join (cost=39439.03..1698014.10 rows=23875 width=38) (actual time=1024.104..8692.892 rows=24374 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1799508 read=227873 dirtied=712 written=30 -> Nested Loop (cost=39437.47..1697564.88 rows=23875 width=16) (actual time=1024.038..8662.285 rows=24374 loops=1) Buffers: shared hit=1799504 read=227873 dirtied=712 written=30 -> Hash Join (cost=39437.17..1689861.29 rows=23875 width=16) (actual time=1024.006..8475.427 rows=24374 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1726268 read=227873 dirtied=712 written=30 -> Nested Loop (cost=406.49..1650144.20 rows=119375 width=20) (actual time=6.881..7378.847 rows=123169 loops=1) Buffers: shared hit=1616221 read=191772 dirtied=712 written=30 -> Nested Loop (cost=406.05..1458067.47 rows=392282 width=16) (actual time=6.709..3371.269 rows=403837 loops=1) Buffers: shared hit=317257 read=154661 dirtied=619 written=22 -> Bitmap Heap Scan on part (cost=405.49..27757.80 rows=13040 width=4) (actual time=6.652..171.399 rows=13440 loops=1) Recheck Cond: ((p_type)::text = 'ECONOMY POLISHED NICKEL'::text) Heap Blocks: exact=11404 Buffers: shared hit=251 read=11237 written=2 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.23 rows=13040 width=0) (actual time=4.486..4.486 rows=13440 loops=1) Index Cond: ((p_type)::text = 'ECONOMY POLISHED NICKEL'::text) Buffers: shared read=84 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.38 rows=31 width=20) (actual time=0.025..0.228 rows=30 loops=13440) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=317006 read=143424 dirtied=619 written=20 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.009..0.009 rows=0 loops=403837) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1298964 read=37111 dirtied=93 written=8 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1013.482..1013.482 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110047 read=36101 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=18.602..916.279 rows=299493 loops=1) Buffers: shared hit=110047 read=36101 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.037..0.088 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=0.005..0.014 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.017..0.017 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=0.011..0.012 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=16.585..172.738 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110045 read=36101 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=10.818..10.818 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> 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=24374) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73236 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.022..0.022 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=0.003..0.006 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.745 ms Execution time: 8729.131 ms (66 rows) COMMIT; COMMIT