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 = 'LARGE PLATED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2193656.72..2193658.55 rows=732 width=38) (actual time=68279.654..68279.655 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=712507 read=297547 dirtied=385 written=3 -> HashAggregate (cost=2193609.08..2193621.89 rows=732 width=38) (actual time=68279.592..68279.594 rows=2 loops=1) Buffers: shared hit=712504 read=297547 dirtied=385 written=3 -> Nested Loop (cost=497163.28..2193113.56 rows=24776 width=38) (actual time=38493.629..68153.566 rows=24514 loops=1) Buffers: shared hit=712504 read=297547 dirtied=385 written=3 -> Nested Loop (cost=497163.28..2186047.45 rows=24776 width=16) (actual time=38493.505..66499.406 rows=24514 loops=1) Buffers: shared hit=663476 read=297547 dirtied=385 written=3 -> Hash Join (cost=497163.28..2178831.44 rows=24780 width=16) (actual time=38493.442..64698.786 rows=24514 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=589792 read=297547 dirtied=385 written=3 -> Nested Loop (cost=0.00..1679381.67 rows=407738 width=16) (actual time=1.708..24686.822 rows=405092 loops=1) Buffers: shared hit=229565 read=244602 dirtied=385 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46920.54 rows=13527 width=4) (actual time=1.621..960.309 rows=13470 loops=1) Index Cond: (p_type = 'LARGE PLATED STEEL'::text) Heap Fetches: 13470 Buffers: shared hit=2 read=11568 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.37 rows=31 width=20) (actual time=0.201..1.741 rows=30 loops=13470) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=229563 read=233034 dirtied=385 -> Hash (cost=485710.98..485710.98 rows=916184 width=8) (actual time=38490.643..38490.643 rows=911915 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=360224 read=52945 written=3 -> Hash Join (cost=136122.93..485710.98 rows=916184 width=8) (actual time=11332.779..37814.314 rows=911915 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=360224 read=52945 written=3 -> Bitmap Heap Scan on orders (cost=97092.31..420340.08 rows=4580918 width=12) (actual time=4792.526..17212.482 rows=4561668 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=249379 read=17641 written=3 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95947.08 rows=4580918 width=0) (actual time=4585.493..4585.493 rows=4579958 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12486 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=6539.914..6539.914 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=110845 read=35304 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=45.153..6309.062 rows=299493 loops=1) Buffers: shared hit=110845 read=35304 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.045..0.101 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=0.008..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.021..0.021 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=0.016..0.018 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=47.136..1239.608 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110843 read=35304 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=36.035..36.035 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.069..0.070 rows=1 loops=24514) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73684 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.061..0.062 rows=1 loops=24514) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49028 Total runtime: 68298.824 ms (64 rows) COMMIT; COMMIT