declare global temporary table customer (cust_id int, cust_name varchar( 20 )) on commit preserve rows not logged;
declare global temporary table payment (pay_id int, cust_id int, pay_date date, card_no varchar( 20 )) with replace on commit preserve rows not logged;

insert into session.customer values ( 1 , 'vova'), ( 2 , 'petya');
insert into session.payment values 
  ( 1 ,  1 , current date, '111-111-111')
, ( 2 ,  1 , current date +  1  day, '111-222-222')
, ( 3 ,  1 , current date +  1  day, '111-333-333')
, ( 4 ,  2 , current date, '222-111-111')
, ( 5 ,  2 , current date +  1  day, '222-222-222')
, ( 6 ,  2 , current date +  1  day, '222-333-333');

select c.*, p.*
from session.customer c
, table(
select p.* 
from session.payment p 
where p.cust_id=c.cust_id 
order by 
--p.pay_date desc
p.pay_id desc
fetch first  1  row only) p;

...
order by 
p.pay_date desc
--p.pay_id desc
...