BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOZAMBIQUE' 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 BRUSHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1699006.59..1699008.42 rows=732 width=38) (actual time=11999.194..11999.195 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=1712731 read=279884 dirtied=859 written=7570 -> HashAggregate (cost=1698958.95..1698971.76 rows=732 width=38) (actual time=11999.119..11999.120 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1712728 read=279884 dirtied=859 written=7570 -> Hash Join (cost=39438.97..1698480.69 rows=23913 width=38) (actual time=1184.566..11952.856 rows=24037 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1712728 read=279884 dirtied=859 written=7570 -> Nested Loop (cost=39437.41..1698030.76 rows=23913 width=16) (actual time=1184.498..11908.979 rows=24037 loops=1) Buffers: shared hit=1712724 read=279884 dirtied=859 written=7570 -> Hash Join (cost=39437.12..1690314.93 rows=23913 width=16) (actual time=1184.476..11678.945 rows=24037 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1640454 read=279884 dirtied=859 written=7570 -> Nested Loop (cost=406.43..1650596.74 rows=119566 width=20) (actual time=7.993..10409.053 rows=120585 loops=1) Buffers: shared hit=1522761 read=251429 dirtied=859 written=7570 -> Nested Loop (cost=406.00..1458048.17 rows=393239 width=16) (actual time=7.575..5204.640 rows=395959 loops=1) Buffers: shared hit=250155 read=214144 dirtied=859 written=6508 -> Bitmap Heap Scan on part (cost=405.43..27749.50 rows=13033 width=4) (actual time=7.493..164.801 rows=13197 loops=1) Recheck Cond: ((p_type)::text = 'LARGE BRUSHED TIN'::text) Heap Blocks: exact=11271 Buffers: shared hit=4300 read=7039 written=169 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.18 rows=13033 width=0) (actual time=5.151..5.151 rows=13197 loops=1) Index Cond: ((p_type)::text = 'LARGE BRUSHED TIN'::text) Buffers: shared read=68 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.43 rows=31 width=20) (actual time=0.034..0.370 rows=30 loops=13197) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=245855 read=207105 dirtied=859 written=6339 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.012..0.012 rows=0 loops=395959) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1272606 read=37285 written=1062 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1172.702..1172.702 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=117693 read=28455 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=23.328..1073.305 rows=299493 loops=1) Buffers: shared hit=117693 read=28455 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.074..0.117 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=0.014..0.025 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: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.019..0.020 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=20.414..202.733 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=117691 read=28455 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.348..13.348 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=0.008..0.008 rows=1 loops=24037) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72270 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.025..0.025 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..0.005 rows=25 loops=1) Buffers: shared hit=1 Planning time: 9.946 ms Execution time: 12000.145 ms (66 rows) COMMIT; COMMIT