Use the @STRRTRIM function to trim trailing spaces.
For this function, Oracle GoldenGate supports the use of an escape sequence to represent characters in a string column in Unicode or in the native character encoding of the Microsoft Windows, UNIX, and Linux operating systems. The target column must be a SQL Unicode data type if any argument is supplied as Unicode.
@STRRTRIM (string)
stringThe name of a character column or a literal string that is enclosed within single quote marks.