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 = 'STANDARD BRUSHED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1698971.11..1698972.94 rows=730 width=38) (actual time=11725.416..11725.418 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=2013301 read=260583 dirtied=1332 written=679 -> HashAggregate (cost=1698923.62..1698936.40 rows=730 width=38) (actual time=11725.350..11725.352 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2013298 read=260583 dirtied=1332 written=679 -> Hash Join (cost=39438.97..1698447.52 rows=23805 width=38) (actual time=1298.217..11685.981 rows=24220 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2013298 read=260583 dirtied=1332 written=679 -> Nested Loop (cost=39437.41..1697999.61 rows=23805 width=16) (actual time=1298.154..11649.250 rows=24220 loops=1) Buffers: shared hit=2013294 read=260583 dirtied=1332 written=679 -> Hash Join (cost=39437.12..1690310.56 rows=23830 width=16) (actual time=1298.123..11448.013 rows=24220 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1940484 read=260583 dirtied=1332 written=679 -> Nested Loop (cost=406.43..1650594.76 rows=119150 width=20) (actual time=7.307..10024.218 rows=120804 loops=1) Buffers: shared hit=1830437 read=224482 dirtied=1332 written=379 -> Nested Loop (cost=406.00..1458046.65 rows=393238 width=16) (actual time=7.247..4035.216 rows=396956 loops=1) Buffers: shared hit=299138 read=165810 dirtied=1052 written=255 -> Bitmap Heap Scan on part (cost=405.43..27749.50 rows=13033 width=4) (actual time=7.168..194.149 rows=13225 loops=1) Recheck Cond: ((p_type)::text = 'STANDARD BRUSHED BRASS'::text) Heap Blocks: exact=11294 Buffers: shared hit=266 read=11111 written=12 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.18 rows=13033 width=0) (actual time=4.929..4.929 rows=13225 loops=1) Index Cond: ((p_type)::text = 'STANDARD BRUSHED BRASS'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.43 rows=31 width=20) (actual time=0.030..0.280 rows=30 loops=13225) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=298872 read=154699 dirtied=1052 written=243 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.014..0.014 rows=0 loops=396956) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1531299 read=58672 dirtied=280 written=124 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1286.089..1286.089 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110047 read=36101 written=300 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=22.832..1166.865 rows=299493 loops=1) Buffers: shared hit=110047 read=36101 written=300 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.058..0.114 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=0.010..0.023 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.023..0.023 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=0.015..0.017 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=20.822..222.250 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110045 read=36101 written=300 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.536..13.536 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 written=2 -> 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=24220) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72810 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.024..0.024 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..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.708 ms Execution time: 11726.764 ms (68 rows) COMMIT; COMMIT