You must have the correct privilege before you can alter the name of a table or the names, types, or number of columns in it. You must also have the correct privileges to set the object modes for constraints and triggers.
You must be the owner of the database object, have Database Administrator privilege in the database, or be granted ALTER privilege for the database object by its owner or a DBA. See the discussion of error -313 for a way to list the owners of tables and users with DBA privilege.