EXPLAIN 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 = 'EUROPE' 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                                                                           
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 Sort  (cost=2856553.34..2856553.40 rows=25 width=34)
   Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount))))
   ->  HashAggregate  (cost=2856552.51..2856552.76 rows=25 width=34)
         Group Key: nation.n_name
         ->  Hash Join  (cost=453450.77..2855850.59 rows=70192 width=34)
               Hash Cond: ((orders.o_custkey = customer.c_custkey) AND (supplier.s_nationkey = customer.c_nationkey))
               ->  Hash Join  (cost=374803.85..2704706.38 rows=1754568 width=46)
                     Hash Cond: (lineitem.l_orderkey = orders.o_orderkey)
                     ->  Hash Join  (cost=4007.53..2012079.24 rows=11785619 width=46)
                           Hash Cond: (lineitem.l_suppkey = supplier.s_suppkey)
                           ->  Seq Scan on lineitem  (cost=0.00..1665268.56 rows=59985856 width=16)
                           ->  Hash  (cost=3757.53..3757.53 rows=20000 width=38)
                                 ->  Hash Join  (cost=2.53..3757.53 rows=20000 width=38)
                                       Hash Cond: (supplier.s_nationkey = nation.n_nationkey)
                                       ->  Seq Scan on supplier  (cost=0.00..3180.00 rows=100000 width=8)
                                       ->  Hash  (cost=2.47..2.47 rows=5 width=30)
                                             ->  Hash Join  (cost=1.07..2.47 rows=5 width=30)
                                                   Hash Cond: (nation.n_regionkey = region.r_regionkey)
                                                   ->  Seq Scan on nation  (cost=0.00..1.25 rows=25 width=34)
                                                   ->  Hash  (cost=1.06..1.06 rows=1 width=4)
                                                         ->  Seq Scan on region  (cost=0.00..1.06 rows=1 width=4)
                                                               Filter: (r_name = 'EUROPE'::bpchar)
                     ->  Hash  (cost=334159.78..334159.78 rows=2233083 width=8)
                           ->  Bitmap Heap Scan on orders  (cost=47385.54..334159.78 rows=2233083 width=8)
                                 Recheck Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone))
                                 ->  Bitmap Index Scan on i_o_orderdate  (cost=0.00..46827.26 rows=2233083 width=0)
                                       Index Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone))
               ->  Hash  (cost=50285.17..50285.17 rows=1500117 width=8)
                     ->  Seq Scan on customer  (cost=0.00..50285.17 rows=1500117 width=8)
(29 rows)