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=1857656.13..1857656.19 rows=25 width=34) (actual time=18180.925..18180.926 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=2101961 read=623517 dirtied=24 written=34145 -> HashAggregate (cost=1857655.30..1857655.55 rows=25 width=34) (actual time=18180.850..18180.854 rows=5 loops=1) Group Key: nation.n_name Buffers: shared hit=2101958 read=623517 dirtied=24 written=34145 -> Hash Join (cost=92224.28..1856923.64 rows=73166 width=34) (actual time=2364.138..18092.335 rows=73056 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=2101958 read=623517 dirtied=24 written=34145 -> Nested Loop (cost=87545.28..1837793.99 rows=1829198 width=46) (actual time=2297.144..16826.922 rows=1825099 loops=1) Buffers: shared hit=2100003 read=623290 dirtied=24 written=34145 -> Hash Join (cost=87544.71..388522.69 rows=457407 width=38) (actual time=2297.105..6696.517 rows=457038 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=261190 read=144711 dirtied=24 written=9896 -> Bitmap Heap Scan on orders (cost=48502.54..336330.07 rows=2287035 width=8) (actual time=1295.563..4086.681 rows=2275543 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=253504 Buffers: shared hit=131332 read=128392 dirtied=24 written=9896 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47930.79 rows=2287035 width=0) (actual time=1196.289..1196.289 rows=2277844 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 -> Hash (cost=35292.17..35292.17 rows=300000 width=38) (actual time=997.640..997.640 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 25258kB Buffers: shared hit=129858 read=16319 -> Nested Loop (cost=905.25..35292.17 rows=300000 width=38) (actual time=21.523..856.541 rows=300963 loops=1) Buffers: shared hit=129858 read=16319 -> Nested Loop (cost=0.14..13.95 rows=5 width=30) (actual time=0.073..0.176 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=0.012..0.046 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.002..0.003 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.022..0.022 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=20.465..156.176 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=129855 read=16319 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.230..13.230 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=9 read=829 -> Index Scan using lineitem_l_orderkey_idx on lineitem (cost=0.56..3.02 rows=15 width=16) (actual time=0.019..0.021 rows=4 loops=457038) Index Cond: (l_orderkey = orders.o_orderkey) Buffers: shared hit=1838813 read=478579 written=24249 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=64.731..64.731 rows=100000 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 4931kB Buffers: shared hit=1952 read=227 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.011..30.897 rows=100000 loops=1) Buffers: shared hit=1952 read=227 Planning time: 5.819 ms Execution time: 18184.628 ms (56 rows) COMMIT; COMMIT