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 '1993-01-01' and o_orderdate < date '1993-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1879458.32..1879458.38 rows=25 width=34) (actual time=15881.164..15881.165 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=1966844 read=762810 dirtied=215 written=29525 -> HashAggregate (cost=1879457.49..1879457.74 rows=25 width=34) (actual time=15881.100..15881.101 rows=5 loops=1) Group Key: nation.n_name Buffers: shared hit=1966841 read=762810 dirtied=215 written=29525 -> Hash Join (cost=93770.36..1878720.13 rows=73736 width=34) (actual time=2322.591..15800.099 rows=72759 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=1966841 read=762810 dirtied=215 written=29525 -> Nested Loop (cost=89091.36..1859478.21 rows=1843408 width=46) (actual time=2252.476..15083.430 rows=1827731 loops=1) Buffers: shared hit=1964659 read=762810 dirtied=215 written=29525 -> Hash Join (cost=89090.79..393475.38 rows=460960 width=38) (actual time=2252.415..6826.130 rows=457079 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=127957 read=281357 dirtied=215 written=9834 -> Bitmap Heap Scan on orders (cost=50048.62..341180.61 rows=2304799 width=8) (actual time=1113.674..4537.607 rows=2277198 loops=1) Recheck Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone)) Heap Blocks: exact=256548 Buffers: shared hit=17884 read=245253 dirtied=215 written=9812 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..49472.43 rows=2304799 width=0) (actual time=1005.929..1005.929 rows=2306268 loops=1) Index Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone)) Buffers: shared read=6589 -> Hash (cost=35292.17..35292.17 rows=300000 width=38) (actual time=1134.865..1134.865 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 25258kB Buffers: shared hit=110073 read=36104 written=22 -> Nested Loop (cost=905.25..35292.17 rows=300000 width=38) (actual time=21.975..1001.403 rows=300963 loops=1) Buffers: shared hit=110073 read=36104 written=22 -> Nested Loop (cost=0.14..13.95 rows=5 width=30) (actual time=0.110..0.170 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=0.011..0.038 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.003..0.004 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.015..0.015 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=18.981..186.648 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110070 read=36104 written=22 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.444..12.444 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=6 read=832 written=22 -> Index Scan using lineitem_l_orderkey_idx on lineitem (cost=0.56..3.03 rows=15 width=16) (actual time=0.015..0.017 rows=4 loops=457079) Index Cond: (l_orderkey = orders.o_orderkey) Buffers: shared hit=1836702 read=481453 written=19691 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=69.473..69.473 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..41.220 rows=100000 loops=1) Buffers: shared hit=2179 Planning time: 6.979 ms Execution time: 15882.821 ms (56 rows) COMMIT; COMMIT