BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 = 'SMALL BURNISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2132032.32..2132034.14 rows=728 width=38) (actual time=34435.722..34435.722 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=742940 read=256441 dirtied=2894 written=1903 -> HashAggregate (cost=2131984.97..2131997.71 rows=728 width=38) (actual time=34435.636..34435.637 rows=2 loops=1) Buffers: shared hit=742937 read=256441 dirtied=2894 written=1903 -> Nested Loop (cost=501582.74..2131523.57 rows=23070 width=38) (actual time=22521.298..34363.524 rows=23923 loops=1) Buffers: shared hit=742937 read=256441 dirtied=2894 written=1903 -> Nested Loop (cost=501582.74..2124944.01 rows=23070 width=16) (actual time=22521.223..34105.606 rows=23923 loops=1) Buffers: shared hit=695091 read=256441 dirtied=2894 written=1903 -> Hash Join (cost=501582.74..2118223.66 rows=23078 width=16) (actual time=22521.190..33549.501 rows=23923 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=623157 read=256441 dirtied=2894 written=1903 -> Nested Loop (cost=0.00..1614500.80 rows=381866 width=16) (actual time=0.474..9724.635 rows=393377 loops=1) Buffers: shared hit=221440 read=242516 dirtied=2894 written=593 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..44052.26 rows=12573 width=4) (actual time=0.366..401.872 rows=13119 loops=1) Index Cond: (p_type = 'SMALL BURNISHED TIN'::text) Heap Fetches: 13119 Buffers: shared hit=2 read=11265 written=27 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..124.59 rows=32 width=20) (actual time=0.074..0.694 rows=30 loops=13119) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=221438 read=231251 dirtied=2894 written=566 -> Hash (cost=490115.34..490115.34 rows=917392 width=8) (actual time=22518.892..22518.892 rows=911074 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35589kB Buffers: shared hit=401714 read=13925 written=1310 -> Hash Join (cost=138628.94..490115.34 rows=917392 width=8) (actual time=5526.141..21939.212 rows=911074 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=401714 read=13925 written=1310 -> Bitmap Heap Scan on orders (cost=99598.32..424709.70 rows=4586959 width=12) (actual time=3487.109..8093.069 rows=4557140 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=256389 read=13101 written=1244 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98451.58 rows=4586959 width=0) (actual time=3331.290..3331.290 rows=4614260 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=435 read=12748 written=1155 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=2038.717..2038.717 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145325 read=824 written=66 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=36.764..1841.223 rows=299493 loops=1) Buffers: shared hit=145325 read=824 written=66 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.043..0.099 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=0.027..0.027 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=0.023..0.025 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=38.842..348.704 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145323 read=824 written=66 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=28.319..28.319 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=9 read=824 written=66 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.020..0.021 rows=1 loops=23923) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=71934 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.007..0.008 rows=1 loops=23923) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=47846 Total runtime: 34447.422 ms (64 rows) COMMIT; COMMIT