select REVERSE(SUBSTR(REVERSE('This.Is.My.Filename.txt'),
position('.' in REVERSE('This.Is.My.Filename.txt')) + 1));
select SUBSTR('This.Is.My.Filename.txt', 1, position('.' in 'This.Is.My.Filename.txt') - 1)
where 'This.Is.My.Filename.txt' like '%.%';
select REVERSE(SUBSTR(REVERSE('This.Is.My.Filename.txt'),
position('.' in REVERSE('This.Is.My.Filename.txt')) + 1))
where 'This.Is.My.Filename' like '%.%';