declare
v_count1 int :=-1;
v_count2 int :=-1;
j int :=0;
diff int :=0;
begin
for i in (select tname from tab) loop
  j:=j+1;
  diff := v_count1 - v_count2;
  execute immediate 'select count(*) from '   || i.tname  into v_count1;
  execute immediate 'select count(*) from '   || i.tname || '@a2_link01' into v_count2;
  dbms_output.put_line(j || ' : ' || i.tname || ' * ' || v_count1 || ' * ' || v_count2 ||  ' * ' || diff);
end loop;
end ;