oracle 12c - select string after last occurrence of a character

Question

I have below string:

ThisSentence.ShouldBe.SplitAfterLastPeriod.Sentence

So I want to select Sentence since it is the string a

Answer 1

And yet another way.

Not sure from a performance standpoint which would be best...

The difference here is that we use -1 to count backwards to find the last . when doing the instr.

  With CTE as 
  (Select 'ThisSentence.ShouldBe.SplitAfterLastPeriod.Sentence' str, length('ThisSentence.ShouldBe.SplitAfterLastPeriod.Sentence') len from dual)
  Select substr(str,instr(str,'.',-1)+1,len-instr(str,'.',-1)+1) from cte;