create trigger tempdb.trg_ins after  insert on tempdb.test_trg 
--Работает
REFERENCING NEW AS NEWROW
FOR EACH ROW        MODE DB2SQL
begin atomic
    declare v_i int;
    set v_i = (select sum(i) from tempdb.test_trg);
end
--Не работает
create trigger tempdb.trg_ins1 after  insert on tempdb.test_trg 
REFERENCING NEW AS NEWROW
FOR EACH ROW        MODE DB2SQL
begin atomic
    declare v_i int;
    select sum(i) into v_i  from tempdb.test_trg;
end