In either case, the easiest way is to drop the entire tablespace that contains the datafile. The steps that are to be executed from within SQL*Plus are: 1. STARTUP MOUNT 2. For each deleted datafile, issue the command ALTER DATABASE DATAFILE ’full path of filename’ OFFLINE [DROP]; Note: You must use the DROP option if the database is in NOARCHIVELOG mode, because you cannot recover this file if you apply incomplete media recovery on it via the command ALTER DATABASE OPEN RESETLOGS. See the SQL Reference for details. 3. ALTER DATABASE OPEN; 4. DROP TABLESPACE INCLUDING CONTENTS [CASCADE CONSTRAINTS];...