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 '1994-01-01' and o_orderdate < date '1994-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2424942.15..2424942.21 rows=25 width=34) (actual time=76193.466..76193.467 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=875226 read=600631 dirtied=253 written=883 -> HashAggregate (cost=2424941.32..2424941.57 rows=25 width=34) (actual time=76193.341..76193.343 rows=5 loops=1) Buffers: shared hit=875223 read=600631 dirtied=253 written=883 -> Hash Join (cost=399359.57..2424208.93 rows=73239 width=34) (actual time=16241.547..76061.556 rows=72312 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=875223 read=600631 dirtied=253 written=883 -> Hash Join (cost=394680.57..2382138.40 rows=1832957 width=46) (actual time=16124.654..72244.753 rows=1823940 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=873041 read=600631 dirtied=253 written=883 -> Seq Scan on lineitem (cost=0.00..1668600.84 rows=60105484 width=16) (actual time=0.045..16195.022 rows=60045603 loops=1) Buffers: shared hit=744533 read=323013 written=1 -> Hash (cost=388951.21..388951.21 rows=458349 width=38) (actual time=16124.062..16124.062 rows=455330 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32016kB Buffers: shared hit=128508 read=277618 dirtied=253 written=882 -> Hash Join (cost=87622.50..388951.21 rows=458349 width=38) (actual time=3686.397..15275.120 rows=455330 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=128508 read=277618 dirtied=253 written=882 -> Bitmap Heap Scan on orders (cost=48580.28..336731.46 rows=2291745 width=8) (actual time=1780.894..6713.993 rows=2278204 loops=1) Recheck Cond: ((o_orderdate >= '1994-01-01'::date) AND (o_orderdate < '1995-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=8140 read=251836 dirtied=253 written=673 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..48007.35 rows=2291745 width=0) (actual time=1646.737..1646.737 rows=2280522 loops=1) Index Cond: ((o_orderdate >= '1994-01-01'::date) AND (o_orderdate < '1995-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=345 read=5877 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=1904.925..1904.925 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21059kB Buffers: shared hit=120368 read=25782 written=209 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=31.970..1209.494 rows=299493 loops=1) Buffers: shared hit=120368 read=25782 written=209 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.048..0.140 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=0.001..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=0.024..0.028 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=25.592..223.982 rows=59899 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=120365 read=25782 written=209 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=17.198..17.198 rows=59899 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=7 read=826 written=4 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=115.580..115.580 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=0.029..69.329 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 76220.008 ms (55 rows) COMMIT; COMMIT