BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue from customer, orders, lineitem, supplier, nation, region where c_custkey = o_custkey and l_orderkey = o_orderkey and l_suppkey = s_suppkey and c_nationkey = s_nationkey and s_nationkey = n_nationkey and n_regionkey = r_regionkey and r_name = 'EUROPE' and o_orderdate >= date '1997-01-01' and o_orderdate < date '1997-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1864194.08..1864194.15 rows=25 width=34) (actual time=17680.987..17680.988 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=2209589 read=516382 dirtied=173 written=10076 -> HashAggregate (cost=1864193.25..1864193.50 rows=25 width=34) (actual time=17680.919..17680.919 rows=5 loops=1) Group Key: nation.n_name Buffers: shared hit=2209586 read=516382 dirtied=173 written=10076 -> Hash Join (cost=92501.57..1863456.65 rows=73660 width=34) (actual time=2692.093..17593.712 rows=73082 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=2209586 read=516382 dirtied=173 written=10076 -> Nested Loop (cost=87822.57..1844229.52 rows=1841537 width=46) (actual time=2624.722..16239.443 rows=1825181 loops=1) Buffers: shared hit=2207404 read=516382 dirtied=173 written=10076 -> Hash Join (cost=87822.01..389624.41 rows=460476 width=38) (actual time=2624.638..7638.181 rows=457040 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=258626 read=147781 dirtied=173 written=1995 -> Bitmap Heap Scan on orders (cost=48779.84..337343.56 rows=2302381 width=8) (actual time=1449.719..4527.062 rows=2275601 loops=1) Recheck Cond: ((o_orderdate >= '1997-01-01'::date) AND (o_orderdate < '1998-01-01 00:00:00'::timestamp without time zone)) Heap Blocks: exact=254010 Buffers: shared hit=148555 read=111675 dirtied=173 written=1975 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..48204.24 rows=2302381 width=0) (actual time=1294.516..1294.516 rows=2282427 loops=1) Index Cond: ((o_orderdate >= '1997-01-01'::date) AND (o_orderdate < '1998-01-01 00:00:00'::timestamp without time zone)) Buffers: shared read=6220 written=241 -> Hash (cost=35292.17..35292.17 rows=300000 width=38) (actual time=1171.292..1171.292 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 25258kB Buffers: shared hit=110071 read=36106 written=20 -> Nested Loop (cost=905.25..35292.17 rows=300000 width=38) (actual time=20.377..1054.600 rows=300963 loops=1) Buffers: shared hit=110071 read=36106 written=20 -> Nested Loop (cost=0.14..13.95 rows=5 width=30) (actual time=0.056..0.129 rows=5 loops=1) Join Filter: (nation.n_regionkey = region.r_regionkey) Rows Removed by Join Filter: 20 Buffers: shared hit=3 -> Index Scan using pk_nation on nation (cost=0.14..12.51 rows=25 width=34) (actual time=0.019..0.053 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.001..0.002 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.013..0.013 rows=1 loops=1) Filter: (r_name = 'EUROPE'::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=18.353..197.346 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110068 read=36106 written=20 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.035..12.035 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=6 read=832 written=5 -> Index Scan using pk_lineitem on lineitem (cost=0.56..3.01 rows=15 width=16) (actual time=0.016..0.017 rows=4 loops=457040) Index Cond: (l_orderkey = orders.o_orderkey) Buffers: shared hit=1948778 read=368601 written=8081 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=64.565..64.565 rows=100000 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 4931kB Buffers: shared hit=2179 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.011..38.928 rows=100000 loops=1) Buffers: shared hit=2179 Planning time: 7.061 ms Execution time: 17686.457 ms (56 rows) COMMIT; COMMIT