drop tablespace ORA-01115 ORA-01110 ORA-15078

由于磁盘组testdg不再需要，决定删除，但由于存储了数据文件不能被删除

SQL> drop diskgroup testdg;
drop diskgroup testdg
*
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15053: diskgroup "TESTDG" contains existing files

删除磁盘组testdg中的数据文件，出现磁盘组之前被强制dismounted的错误信息而不能被删除,该磁盘组确实由于一块磁盘出现故障后，被ASM强制dismount了，后面又被手动使用force选项强制mount过

SQL> drop tablespace t_cs including contents and datafiles;
drop tablespace t_cs including contents and datafiles
*
ERROR at line 1:
ORA-01115: IO error reading block from file 11 (block # 1)
ORA-01110: data file 11: '+TESTDG/jyrac/datafile/t_cs.256.932894807'
ORA-15078: ASM diskgroup was forcibly dismounted

在这种情况下我们可以先将数据文件设置为offline，再执行删除操作

SQL> alter database datafile '+TESTDG/jyrac/datafile/t_cs.256.932894807' offline drop;

Database altered.

SQL> drop tablespace t_cs including contents and datafiles;

Tablespace dropped.

SQL> select tablespace_name from dba_tablespaces;

TABLESPACE_NAME
------------------------------
SYSTEM
SYSAUX
UNDOTBS1
TEMP
USERS
UNDOTBS2
EXAMPLE
TEST
CS
CS_STRIPE_COARSE
NOT_IMPORTANT

11 rows selected.