-- 假如undo表空间undotbs不能释放空间,重建之

    -- 创建备用undo表空间
    create undo tablespace newundotbs datafile '$ORA_DATA/newundotbs01.dbf' size 1000m
    /   
    -- 切换undo表空间
    alter system set undo_tablespace=newundotbs scope=spfile
    /
    shutdown immediate
    /
    startup
    /
    -- drop原表空间
    drop tablespace undotbs including contents and datafiles
    /
    -- 创建原undo表空间
    create undo tablespace undotbs datafile '$ORA_DATA/undotbs01.dbf' size 1000m
    /
    -- 切换undo表空间
    alter system set undo_tablespace=undotbs scope=spfile
    /
    -- 关闭重起并把备用undo表空间drop
    shutdown immediate
    /
    startup
    /
    drop tablespace newundotbs including contents and datafiles
    /