The function releases all previous memory or file resources associated with the variable and resets the length of the file to zero. The function does not write the current value of the CLOB variable to the file upon making the association. However, future changes to the variable, such as setClobFromString() or reading from a database into the variable, write the value of the variable to the associated file.
To save an existing value of the CLOB variable into a file, use the updateClobToFile() system function, which does not use a temp file.