Specifies whether the existing data files making up the database should be reused. That is, specifying DESTROY=y causes Import to include the REUSE option in the data file clause of the SQL CREATE TABLESPACE statement, which causes Import to reuse the original database's data files after deleting their contents.
Note that the export file contains the data file names used in each tablespace. If you specify DESTROY=y and attempt to create a second database on the same system (for testing or other purposes), then the Import utility will overwrite the first database's data files when it creates the tablespace. In this situation you should use the default, DESTROY=n, so that an error occurs if the data files already exist when the tablespace is created. Also, when you need to import into the original database, you will need to specify IGNORE=y to add to the existing data files without replacing them.