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 '1995-01-01' and o_orderdate < date '1995-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2425894.46..2425894.52 rows=25 width=34) (actual time=74618.860..74618.860 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=1260097 read=216864 written=35 -> HashAggregate (cost=2425893.63..2425893.88 rows=25 width=34) (actual time=74618.762..74618.764 rows=5 loops=1) Buffers: shared hit=1260094 read=216864 written=35 -> Hash Join (cost=398793.56..2425166.96 rows=72667 width=34) (actual time=15282.473..74479.926 rows=72818 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=1260094 read=216864 written=35 -> Hash Join (cost=394114.56..2383388.25 rows=1818652 width=46) (actual time=15173.337..70947.164 rows=1818187 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=1258759 read=216017 written=35 -> Seq Scan on lineitem (cost=0.00..1670260.77 rows=60165277 width=16) (actual time=0.023..15652.294 rows=60045379 loops=1) Buffers: shared hit=888632 read=179976 written=3 -> Hash (cost=388429.90..388429.90 rows=454773 width=38) (actual time=15172.751..15172.751 rows=454919 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 31987kB Buffers: shared hit=370127 read=36041 written=32 -> Hash Join (cost=87219.22..388429.90 rows=454773 width=38) (actual time=5089.923..14322.524 rows=454919 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=370127 read=36041 written=32 -> Bitmap Heap Scan on orders (cost=48177.00..336312.96 rows=2273864 width=8) (actual time=3893.267..6963.954 rows=2277879 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=225015 read=35214 written=32 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47608.54 rows=2273864 width=0) (actual time=3760.161..3760.161 rows=2282432 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Buffers: shared read=6221 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=1195.908..1195.908 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21055kB Buffers: shared hit=145112 read=827 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=30.216..1025.216 rows=299436 loops=1) Buffers: shared hit=145112 read=827 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.050..0.154 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=0.010..0.057 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=0.021..0.023 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=26.929..181.268 rows=59887 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=145109 read=827 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=18.514..18.514 rows=59887 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=7 read=827 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=108.655..108.655 rows=100000 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 3907kB Buffers: shared hit=1332 read=847 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.008..63.538 rows=100000 loops=1) Buffers: shared hit=1332 read=847 Total runtime: 74642.377 ms (55 rows) COMMIT; COMMIT