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 = 'MEDIUM BRUSHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1714653.93..1714655.75 rows=727 width=38) (actual time=14608.250..14608.251 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=1707690 read=316369 written=5356 -> HashAggregate (cost=1714606.66..1714619.38 rows=727 width=38) (actual time=14608.184..14608.186 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1707687 read=316369 written=5356 -> Hash Join (cost=39448.73..1714126.26 rows=24020 width=38) (actual time=1822.639..14558.795 rows=24406 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1707687 read=316369 written=5356 -> Nested Loop (cost=39447.17..1713674.32 rows=24020 width=16) (actual time=1822.572..14513.070 rows=24406 loops=1) Buffers: shared hit=1707683 read=316369 written=5356 -> Hash Join (cost=39446.88..1705923.62 rows=24021 width=16) (actual time=1822.514..14276.289 rows=24406 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1634475 read=316221 written=5353 -> Nested Loop (cost=416.19..1666202.34 rows=120103 width=20) (actual time=16.977..12324.159 rows=122581 loops=1) Buffers: shared hit=1499699 read=304849 written=5353 -> Nested Loop (cost=415.76..1471571.35 rows=397503 width=16) (actual time=16.252..5934.995 rows=403176 loops=1) Buffers: shared hit=254869 read=216116 written=3894 -> Bitmap Heap Scan on part (cost=411.04..28006.04 rows=13240 width=4) (actual time=16.100..86.915 rows=13420 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM BRUSHED NICKEL'::text) Heap Blocks: exact=11412 Buffers: shared hit=11314 read=182 written=1 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.73 rows=13240 width=0) (actual time=12.391..12.391 rows=13420 loops=1) Index Cond: ((p_type)::text = 'MEDIUM BRUSHED NICKEL'::text) Buffers: shared hit=1 read=83 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.043..0.422 rows=30 loops=13420) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=403703 Buffers: shared hit=243555 read=215934 written=3893 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.031..0.031 rows=30 loops=13420) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=42229 read=13557 written=285 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.015..0.015 rows=0 loops=403176) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1244830 read=88733 written=1459 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1801.352..1801.352 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=134776 read=11372 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=37.135..1636.503 rows=299493 loops=1) Buffers: shared hit=134776 read=11372 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.091..0.158 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=0.012..0.026 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.033..0.033 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=0.022..0.024 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=31.971..311.284 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=134774 read=11372 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=22.219..22.219 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=11 read=821 -> 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=24406) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73208 read=148 written=3 -> 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=0.006..0.009 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.770 ms Execution time: 14609.325 ms (70 rows) COMMIT; COMMIT