oracle删除表后怎么清理磁盘空间（Oracle 删除用户和表空间详细介绍）

drop user ×× cascade

DROP TABLESPACE tablespace_name INCLUDING CONTENTS AND DATAFILES;

create table MTUSEFULSPACE
(
  ID Number(4) NOT NULL PRIMARY KEY,
  USERNAME varchar2(30),
  TABLESPACENAME varchar2(60),
  OWNERNAME varchar2(30)
);

declare icount number(2);
    tempspace varchar2(60);
begin
 for curTable in (select username as allusr,default_tablespace as alltblspace from dba_users)
 loop
 tempspace :=curTable.alltblspace;
 dbms_output.put_line(tempspace);
 select count(TABLESPACENAME) into icount from MTUSEFULSPACE where TABLESPACENAME = tempspace;
 if icount=0 then
  DROP TABLESPACE tempspace INCLUDING CONTENTS AND DATAFILES;
 end if;
 commit;
 end loop;
end;

ORA-06550: 第 10 行, 第 5 列: 
PLS-00103: 出现符号 "DROP"在需要下列之一时：
 begin case declare exit
  for goto if loop mod null pragma raise return select update
  while with <an identifier>
  <a double-quoted delimited-identifier> <a bind variable> <<
  close current delete fetch lock insert open rollback
  savepoint set sql execute commit forall merge pipe
06550. 00000 - "line %s, column %s:\n%s"
*Cause:  Usually a PL/SQL compilation error.
*Action:

select t1.name,t2.name from v$tablespace t1, v$datafile t2 where t1.ts# = t2.ts#;

drop tablespace tablespace_name;

drop tablespace tablespace_name including contents;

drop tablespace tablespace_name including datafiles;

drop tablespace tablespace_name including contents and datafiles;

drop tablespace tablespace_name including contents and datafiles CASCADE CONSTRAINTS;