explain select  count(distinct(b.customer_id)) as members,              
                sum(b.total_loyalty) as sales,
                count(b.customer_id) as visits,
                c.attr_cd, 
                c.attr_type_cd, 
                c.description as description 
from            sc_customer_attr a, 
                sc_add_points b, 
                sc_attr c 
where            exists (select z.customer_id  
                        from (select d.customer_id, 
                                     sum(d.total_loyalty) as points       
                               from  sc_add_points d  
                               where  d.transdate >= 19980100.000000  and    
                                      d.transdate <= 20020931.000000  and 
                                      d.company_cd = 1 and d.branch_cd = 13  and                                      a.customer_id = d.customer_id       
                               group by d.customer_id       
                               order by points desc  
                               limit 100 ) as z
                       )  and
                 a.attr_cd = c.attr_cd and
                 a.attr_type_cd = c.attr_type_cd and
                 a.attr_type_cd = 2           and
                 a.company_cd = c.company_cd and
                 b.customer_id = a.customer_id
group by         c.attr_type_cd, 
                 c.attr_cd, 
                 c.description  
order by         c.description asc  
LIMIT 10 OFFSET 0;