@Description("converts all the alphabets in the string to upper case") @ScalarFunction @SqlType(VarcharType.class) public static Slice upper(@SqlType(VarcharType.class) Slice slice) { Slice upper = Slices.allocate(slice.length()); for (int i = 0; i < slice.length(); i++) { upper.setByte(i, Ascii.toUpperCase((char) slice.getByte(i))); } return upper; }