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=2436917.08..2436917.15 rows=25 width=34) (actual time=85223.312..85223.312 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=1139083 read=343585 dirtied=4 written=34 -> HashAggregate (cost=2436916.25..2436916.50 rows=25 width=34) (actual time=85223.204..85223.208 rows=5 loops=1) Buffers: shared hit=1139080 read=343585 dirtied=4 written=34 -> Hash Join (cost=401478.31..2436182.44 rows=73381 width=34) (actual time=12282.214..85002.614 rows=72514 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=1139080 read=343585 dirtied=4 written=34 -> Hash Join (cost=396799.31..2394079.63 rows=1834500 width=46) (actual time=12142.821..80353.218 rows=1824605 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=1138989 read=341494 dirtied=4 written=34 -> Seq Scan on lineitem (cost=0.00..1676908.88 rows=60405288 width=16) (actual time=0.030..23375.588 rows=60045310 loops=1) Buffers: shared hit=743136 read=329720 dirtied=4 written=2 -> Hash (cost=391065.13..391065.13 rows=458735 width=38) (actual time=12142.085..12142.085 rows=455771 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32047kB Buffers: shared hit=395853 read=11774 written=32 -> Hash Join (cost=88430.35..391065.13 rows=458735 width=38) (actual time=2432.143..11829.385 rows=455771 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=395853 read=11774 written=32 -> Bitmap Heap Scan on orders (cost=49388.13..338834.27 rows=2293676 width=8) (actual time=1445.348..4975.557 rows=2279082 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=250527 read=10950 written=32 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..48814.71 rows=2293676 width=0) (actual time=1299.890..1299.890 rows=2292541 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=6448 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=986.344..986.344 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21059kB Buffers: shared hit=145326 read=824 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=31.253..846.732 rows=299493 loops=1) Buffers: shared hit=145326 read=824 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.055..0.148 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..0.041 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..0.033 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=22.691..151.715 rows=59899 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=145323 read=824 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=14.925..14.925 rows=59899 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=9 read=824 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=138.378..138.378 rows=100000 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 3907kB Buffers: shared hit=88 read=2091 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.013..87.151 rows=100000 loops=1) Buffers: shared hit=88 read=2091 Total runtime: 85239.409 ms (55 rows) COMMIT; COMMIT