EXPLAIN select cntrycode, count(*) as numcust, sum(c_acctbal) as totacctbal from ( select substr(c_phone, 1, 2) as cntrycode, c_acctbal from customer where substr(c_phone, 1, 2) in ('29', '24', '13', '17', '11', '10', '12') and c_acctbal > ( select avg(c_acctbal) from customer where c_acctbal > 0.00 and substr(c_phone, 1, 2) in ('29', '24', '13', '17', '11', '10', '12') ) and not exists ( select * from orders where o_custkey = c_custkey ) ) as vip group by cntrycode order by cntrycode;
             plan              
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             sort             
                              
            groupby           
                              
              map             
                              
         leftantijoin         
         hash                 
                              
        join         tablescan
        bnl          orders   
                              
  groupby  tablescan          
           customer           
 tablescan                    
 customer                     
(16 rows)