title: Change external table BADFILE, LOGFILE and DISCARDFILE parameters only
body: <p>I have several external tables used to read file data into the DB each one for a particular file specification.</p>
  
  <p>For files of a single format a table is reused by pointing it at a new default directory and new file name. This is working fine except I now need to dynamically change the BADFILE, LOGFILE and DISCARDFILE parameters whilst keeping the rest of the access parameters unchanged. </p>
  
  <p>Is there a direct way to do this without having to respecify all the other access parameters (column transformations filed delimiters etc.) as well?</p>