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 = 'MEDIUM BURNISHED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1757688.82..1757690.65 rows=732 width=38) (actual time=11155.616..11155.617 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=1802918 read=221727 dirtied=88 written=6101 -> HashAggregate (cost=1757641.18..1757653.99 rows=732 width=38) (actual time=11155.553..11155.554 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1802915 read=221727 dirtied=88 written=6101 -> Hash Join (cost=39459.26..1757141.34 rows=24992 width=38) (actual time=863.631..11113.095 rows=24288 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1802915 read=221727 dirtied=88 written=6101 -> Nested Loop (cost=39457.70..1756671.18 rows=24992 width=16) (actual time=863.567..11072.995 rows=24288 loops=1) Buffers: shared hit=1802911 read=221727 dirtied=88 written=6101 -> Hash Join (cost=39457.41..1748607.21 rows=24992 width=16) (actual time=863.542..10855.879 rows=24288 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1729913 read=221727 dirtied=88 written=6101 -> Nested Loop (cost=426.72..1708858.01 rows=124958 width=20) (actual time=8.016..9898.820 rows=122084 loops=1) Buffers: shared hit=1584946 read=220546 dirtied=88 written=6097 -> Nested Loop (cost=426.29..1507620.95 rows=410974 width=16) (actual time=7.942..4868.530 rows=402929 loops=1) Buffers: shared hit=289689 read=183479 dirtied=88 written=5016 -> Bitmap Heap Scan on part (cost=421.57..28406.89 rows=13567 width=4) (actual time=7.831..188.267 rows=13437 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM BURNISHED COPPER'::text) Heap Blocks: exact=11551 Buffers: shared hit=1929 read=9706 written=206 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..418.18 rows=13567 width=0) (actual time=5.413..5.413 rows=13437 loops=1) Index Cond: ((p_type)::text = 'MEDIUM BURNISHED COPPER'::text) Buffers: shared read=84 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.043..0.337 rows=30 loops=13437) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=405752 Buffers: shared hit=287760 read=173773 dirtied=88 written=4810 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.028..0.028 rows=30 loops=13437) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=41452 read=14329 written=366 -> 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=402929) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1295257 read=37067 written=1081 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=851.944..851.944 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=144967 read=1181 written=4 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=22.199..762.884 rows=299493 loops=1) Buffers: shared hit=144967 read=1181 written=4 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.043..0.074 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=0.005..0.014 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=19.614..141.286 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=144965 read=1181 written=4 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.857..12.857 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 written=4 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.007..0.008 rows=1 loops=24288) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72998 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.020..0.020 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=0.003..0.005 rows=25 loops=1) Buffers: shared hit=1 Planning time: 8.478 ms Execution time: 11156.686 ms (70 rows) COMMIT; COMMIT