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=2428233.18..2428233.24 rows=25 width=34) (actual time=108402.935..108402.936 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=705603 read=772892 dirtied=253 written=18 -> HashAggregate (cost=2428232.35..2428232.60 rows=25 width=34) (actual time=108402.843..108402.847 rows=5 loops=1) Buffers: shared hit=705600 read=772892 dirtied=253 written=18 -> Hash Join (cost=399120.43..2427504.17 rows=72818 width=34) (actual time=22662.097..108147.305 rows=72526 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=705600 read=772892 dirtied=253 written=18 -> Hash Join (cost=394441.43..2385688.71 rows=1820414 width=46) (actual time=22487.853..103071.593 rows=1824442 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=703418 read=772892 dirtied=253 written=18 -> Seq Scan on lineitem (cost=0.00..1671917.42 rows=60225142 width=16) (actual time=0.024..31075.611 rows=60045303 loops=1) Buffers: shared hit=468919 read=600747 -> Hash (cost=388751.25..388751.25 rows=455214 width=38) (actual time=22487.111..22487.111 rows=455742 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32045kB Buffers: shared hit=234499 read=172145 dirtied=253 written=18 -> Hash Join (cost=87241.82..388751.25 rows=455214 width=38) (actual time=4542.625..21885.008 rows=455742 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=234499 read=172145 dirtied=253 written=18 -> Bitmap Heap Scan on orders (cost=48199.60..336621.64 rows=2276069 width=8) (actual time=2146.440..11181.035 rows=2279058 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=122453 read=138041 dirtied=253 written=18 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47630.59 rows=2276069 width=0) (actual time=1970.306..1970.306 rows=2285733 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=6225 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=2395.860..2395.860 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21059kB Buffers: shared hit=112046 read=34104 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=32.339..2103.976 rows=299493 loops=1) Buffers: shared hit=112046 read=34104 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.055..0.178 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=0.012..0.059 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..0.035 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=35.282..394.338 rows=59899 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=112043 read=34104 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=24.546..24.546 rows=59899 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=7 read=826 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=173.488..173.488 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=0.018..89.843 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 108435.738 ms (55 rows) COMMIT; COMMIT