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 = 'AFRICA' 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=2431441.03..2431441.10 rows=25 width=34) (actual time=120229.042..120229.044 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=918324 read=561518 dirtied=257 written=24 -> HashAggregate (cost=2431440.20..2431440.45 rows=25 width=34) (actual time=120228.946..120228.949 rows=5 loops=1) Buffers: shared hit=918321 read=561518 dirtied=257 written=24 -> Hash Join (cost=400016.68..2430707.94 rows=73226 width=34) (actual time=22525.236..119968.832 rows=72533 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=918321 read=561518 dirtied=257 written=24 -> Hash Join (cost=395337.68..2388672.66 rows=1831201 width=46) (actual time=22364.448..115304.891 rows=1824731 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=916139 read=561518 dirtied=257 written=24 -> Seq Scan on lineitem (cost=0.00..1673595.31 rows=60285531 width=16) (actual time=0.031..44243.849 rows=60046221 loops=1) Buffers: shared hit=558999 read=511741 dirtied=3 -> Hash (cost=389613.83..389613.83 rows=457908 width=38) (actual time=22363.442..22363.442 rows=455787 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32048kB Buffers: shared hit=357140 read=49777 dirtied=254 written=24 -> Hash Join (cost=87571.89..389613.83 rows=457908 width=38) (actual time=3354.719..21195.609 rows=455787 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=357140 read=49777 dirtied=254 written=24 -> Bitmap Heap Scan on orders (cost=48529.67..337406.76 rows=2289539 width=8) (actual time=1874.406..11746.676 rows=2279107 loops=1) Recheck Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=210990 read=49777 dirtied=254 written=24 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47957.29 rows=2289539 width=0) (actual time=1749.083..1749.083 rows=2288014 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 hit=2 read=6243 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=1479.119..1479.119 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21059kB Buffers: shared hit=146150 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=28.455..1273.820 rows=299493 loops=1) Buffers: shared hit=146150 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.094..0.222 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=0.045..0.091 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=0.027..0.034 rows=1 loops=1) Filter: (r_name = 'AFRICA'::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=25.514..231.147 rows=59899 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=146147 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=17.083..17.083 rows=59899 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=833 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=159.493..159.493 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=0.019..111.169 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 120258.211 ms (55 rows) COMMIT; COMMIT