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 = 'STANDARD ANODIZED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1719481.92..1719483.75 rows=732 width=38) (actual time=10546.718..10546.719 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=1768096 read=228153 dirtied=180 written=187 -> HashAggregate (cost=1719434.28..1719447.09 rows=732 width=38) (actual time=10546.655..10546.657 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1768093 read=228153 dirtied=180 written=187 -> Hash Join (cost=39448.99..1718948.18 rows=24305 width=38) (actual time=1037.702..10506.580 rows=24301 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1768093 read=228153 dirtied=180 written=187 -> Nested Loop (cost=39447.42..1718490.90 rows=24305 width=16) (actual time=1037.638..10469.642 rows=24301 loops=1) Buffers: shared hit=1768089 read=228153 dirtied=180 written=187 -> Hash Join (cost=39447.13..1710648.58 rows=24305 width=16) (actual time=1037.618..10263.245 rows=24301 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1695063 read=228153 dirtied=180 written=187 -> Nested Loop (cost=416.45..1670919.12 rows=121526 width=20) (actual time=7.718..9151.005 rows=120522 loops=1) Buffers: shared hit=1573881 read=203187 dirtied=180 written=17 -> Nested Loop (cost=416.01..1475216.88 rows=399684 width=16) (actual time=7.565..4465.346 rows=396924 loops=1) Buffers: shared hit=288199 read=176194 dirtied=109 written=13 -> Bitmap Heap Scan on part (cost=411.29..28047.06 rows=13273 width=4) (actual time=7.452..178.422 rows=13234 loops=1) Recheck Cond: ((p_type)::text = 'STANDARD ANODIZED STEEL'::text) Heap Blocks: exact=11271 Buffers: shared hit=1557 read=9796 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.98 rows=13273 width=0) (actual time=5.079..5.079 rows=13234 loops=1) Index Cond: ((p_type)::text = 'STANDARD ANODIZED STEEL'::text) Buffers: shared read=82 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.041..0.313 rows=30 loops=13234) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=398059 Buffers: shared hit=286642 read=166398 dirtied=109 written=13 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.027..0.027 rows=30 loops=13234) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39602 read=15379 written=1 -> 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=396924) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1285682 read=26993 dirtied=71 written=4 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1026.798..1026.798 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=121182 read=24966 written=170 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.901..930.820 rows=299493 loops=1) Buffers: shared hit=121182 read=24966 written=170 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.048..0.079 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..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.020..0.020 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=0.014..0.016 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=19.590..174.463 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=121180 read=24966 written=170 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.682..12.682 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=0.007..0.007 rows=1 loops=24301) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73026 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.023..0.023 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=0.004..0.009 rows=25 loops=1) Buffers: shared hit=1 Planning time: 8.358 ms Execution time: 10547.500 ms (70 rows) COMMIT; COMMIT