1. 表空间离线

   SQL> alter tablespace  rcat offile；

2.删除用户

    SQL>drop user ractowner cascade

3.删除表空间以及数据文件

    DROP TABLESPACE rcat INCLUDING CONTENTS AND DATAFILES;

4.使用RMAN查看 .dbf文件 是否还存在。

RMAN> report schema;

Report of database schema for database with db_unique_name ORCL

List of Permanent Datafiles
===========================
File Size(MB) Tablespace           RB segs Datafile Name
---- -------- -------------------- ------- ------------------------
1    720      SYSTEM               ***     +DATA/orcl/datafile/system.256.894905947
2    610      SYSAUX               ***     +DATA/orcl/datafile/sysaux.257.894905947
3    110      UNDOTBS1             ***     +DATA/orcl/datafile/undotbs1.258.894905947
4    5        USERS                ***     +DATA/orcl/datafile/users.259.894905947
5    345      EXAMPLE              ***     +DATA/orcl/datafile/example.265.894906137

List of Temporary Files
=======================
File Size(MB) Tablespace           Maxsize(MB) Tempfile Name
---- -------- -------------------- ----------- --------------------
1    29       TEMP                 32767       +DATA/orcl/tempfile/temp.264.894906125

RMAN>