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 = 'AMERICA' and o_orderdate >= date '1996-01-01' and o_orderdate < date '1996-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2428363.67..2428363.74 rows=25 width=34) (actual time=131839.088..131839.088 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=848748 read=629545 dirtied=259 written=65 -> HashAggregate (cost=2428362.84..2428363.09 rows=25 width=34) (actual time=131839.007..131839.009 rows=5 loops=1) Buffers: shared hit=848745 read=629545 dirtied=259 written=65 -> Hash Join (cost=399205.11..2427634.28 rows=72856 width=34) (actual time=24059.712..131530.614 rows=73297 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=848745 read=629545 dirtied=259 written=65 -> Hash Join (cost=394526.11..2385787.60 rows=1821956 width=46) (actual time=23903.090..126061.550 rows=1824346 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=846563 read=629545 dirtied=259 written=65 -> Seq Scan on lineitem (cost=0.00..1671916.62 rows=60225062 width=16) (actual time=0.021..48529.147 rows=60045303 loops=1) Buffers: shared hit=532516 read=537150 -> Hash (cost=388831.11..388831.11 rows=455600 width=38) (actual time=23902.517..23902.517 rows=456308 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32085kB Buffers: shared hit=314047 read=92395 dirtied=259 written=65 -> Hash Join (cost=87281.61..388831.11 rows=455600 width=38) (actual time=5864.730..23289.494 rows=456308 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=314047 read=92395 dirtied=259 written=65 -> Bitmap Heap Scan on orders (cost=48239.40..336690.40 rows=2278000 width=8) (actual time=2005.118..11451.775 rows=2284009 loops=1) Recheck Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=201404 read=59099 dirtied=259 written=8 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47669.90 rows=2278000 width=0) (actual time=1846.103..1846.103 rows=2290810 loops=1) Index Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=323 read=5916 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=3859.166..3859.166 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21055kB Buffers: shared hit=112643 read=33296 written=57 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=24.793..3609.783 rows=299436 loops=1) Buffers: shared hit=112643 read=33296 written=57 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.061..0.192 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=0.00..12.63 rows=25 width=34) (actual time=0.016..0.075 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.002..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=0.026..0.027 rows=1 loops=1) Filter: (r_name = 'AMERICA'::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=36.004..696.601 rows=59887 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=112640 read=33296 written=57 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=25.996..25.996 rows=59887 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=8 read=826 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=156.322..156.322 rows=100000 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 3907kB Buffers: shared hit=2179 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.012..112.066 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 131860.885 ms (55 rows) COMMIT; COMMIT