删除users表空间

原来的数据库用户默认的表空间都是users，现在需要做数据迁移，在导出表空间，cp数据文件到目标数据库之后，需要进行将导出的表空间imp导入，但导入时候报错：ORA-29349: tablespace 'USERS' already exists，很明显用exp做表空间迁移时候目标数据库是不能有与导入的表空间相同的表空间，因此需要将目标数据库已存在的表空间删除，即users表空间。如下：

 

SQL> drop tablespace users including contents and datafiles;
drop tablespace users including contents and datafiles
*
ERROR at line 1:
ORA-12919: Can not drop the default permanent tablespace

SQL> alter database default tablespace system;

Database altered.

SQL> drop tablespace users including contents and datafiles;
drop tablespace users including contents and datafiles
*
ERROR at line 1:
ORA-22868: table with LOBs contains segments in different tablespaces

 

 

以下是引自一位高手的测试实验：

 

SQL> drop tablespace users including contents;
drop tablespace users including contents
*
ERROR at line 1:
ORA-22868: table with LOBs contains segments in different tablespaces

由于表空间不为空，因此需要INCLUDING CONTENTS方式删除表空间，但是这时出现了ORA-22868错误。

错误信息很明确，应该是USERS表空间中包含了LOB表，而LOB表中的LOB对象存储在USERS表空间之外的地方。

只需要找到这些对象并删除就可以解决这个问题：

SQL> col owner format a15
SQL> col tablespace_name format a15
SQL> col column_name format a30
SQL> select a.owner, a.table_name, b.column_name, b.tablespace_name
2 from dba_tables a, dba_lobs b
3 where a.owner = b.owner
4 and a.table_name = b.table_name
5 and a.tablespace_name = 'USERS'
6 and b.tablespace_name != 'USERS';

no rows selected

SQL> select a.owner, a.table_name, b.column_name, b.tablespace_name
2 from dba_tables a, dba_lobs b
3 where a.owner = b.owner
4 and a.table_name = b.table_name
5 and a.tablespace_name = 'USERS';

no rows selected

奇怪的是，并没有符合表处于USERS表空间中，而LOB对象在USERS表空间之外的LOB对象，事实上，所有包含LOB的表，都不在USERS表空间中。

那么Oracle为什么会出现上面的错误呢：

SQL> select count(*)
2 from dba_lobs
3 where tablespace_name = 'USERS';

COUNT(*)
----------
10

SQL> select a.owner, a.table_name, b.column_name, b.tablespace_name
2 from dba_tables a, dba_lobs b
3 where a.owner = b.owner
4 and a.table_name = b.table_name
5 and b.tablespace_name = 'USERS';

no rows selected

SQL> select owner, table_name, column_name, tablespace_name
2 from dba_lobs
3 where tablespace_name = 'USERS';

OWNER TABLE_NAME COLUMN_NAME TABLESPACE_NAME
----- ------------------ -------------------------------------------------- ---------------
OE LINEITEM_TABLE "PART"."SYS_XDBPD$" USERS
OE LINEITEM_TABLE SYS_XDBPD$ USERS
OE ACTION_TABLE SYS_XDBPD$ USERS
OE PURCHASEORDER "XMLDATA"."LINEITEMS"."SYS_XDBPD$" USERS
OE PURCHASEORDER "XMLDATA"."SHIPPING_INSTRUCTIONS"."SYS_XDBPD$" USERS
OE PURCHASEORDER "XMLDATA"."REJECTION"."SYS_XDBPD$" USERS
OE PURCHASEORDER "XMLDATA"."ACTIONS"."SYS_XDBPD$" USERS
OE PURCHASEORDER "XMLDATA"."SYS_XDBPD$" USERS
OE PURCHASEORDER "XMLEXTRA"."EXTRADATA" USERS
OE PURCHASEORDER "XMLEXTRA"."NAMESPACES" USERS

10 rows selected.

查询发现，USERS表空间中包含了10个LOB对象。但是关联DBA_TABLES进行查询，却发现找不到任何的记录。

SQL> SELECT OWNER, OBJECT_NAME, OBJECT_TYPE
2 FROM DBA_OBJECTS
3 WHERE OBJECT_NAME = 'ACTION_TABLE';

OWNER OBJECT_NAME OBJECT_TYPE
------------------------------ ------------------------------ -------------------
OE ACTION_TABLE TABLE

SQL> SELECT OWNER, TABLE_NAME, TABLESPACE_NAME
2 FROM DBA_TABLES
3 WHERE TABLE_NAME = 'ACTION_TABLE';

no rows selected

从DBA_OBJECTS视图中可以看到这个对象，且对象类型为TABLE，而在DBA_TABLES中却找不到表信息，难道在执行CONVERT DATABASE命令过程，造成了数据字典的不一致。

查询一下DBA_TABLES视图信息：

SQL> SET LONG 10000
SQL> SELECT TEXT
2 FROM DBA_VIEWS
3 WHERE VIEW_NAME = 'DBA_TABLES';

TEXT
--------------------------------------------------------------------------------
select u.name, o.name, decode(bitand(t.property,2151678048), 0, ts.name, null),
decode(bitand(t.property, 1024), 0, null, co.name),
decode((bitand(t.property, 512)+bitand(t.flags, 536870912)),
0, null, co.name),
decode(bitand(t.trigflag, 1073741824), 1073741824, 'UNUSABLE', 'VALID'),
decode(bitand(t.property, 32+64), 0, mod(t.pctfree$, 100), 64, 0, null),
decode(bitand(ts.flags, 32), 32, to_number(NULL),
decode(bitand(t.property, 32+64), 0, t.pctused$, 64, 0, null)),
decode(bitand(t.property, 32), 0, t.initrans, null),
decode(bitand(t.property, 32), 0, t.maxtrans, null),
s.iniexts * ts.blocksize,
decode(bitand(ts.flags, 3), 1, to_number(NULL),
s.extsize * ts.blocksize),
s.minexts, s.maxexts,
decode(bitand(ts.flags, 3), 1, to_number(NULL),
s.extpct),
decode(bitand(ts.flags, 32), 32, to_number(NULL),
decode(bitand(o.flags, 2), 2, 1, decode(s.lists, 0, 1, s.lists))),
decode(bitand(ts.flags, 32), 32, to_number(NULL),
decode(bitand(o.flags, 2), 2, 1, decode(s.groups, 0, 1, s.groups))),
decode(bitand(t.property, 32+64), 0,
decode(bitand(t.flags, 32), 0, 'YES', 'NO'), null),
decode(bitand(t.flags,1), 0, 'Y', 1, 'N', '?'),
t.rowcnt,
decode(bitand(t.property, 64), 0, t.blkcnt, null),
decode(bitand(t.property, 64), 0, t.empcnt, null),
t.avgspc, t.chncnt, t.avgrln, t.avgspc_flb,
decode(bitand(t.property, 64), 0, t.flbcnt, null),
lpad(decode(t.degree, 32767, 'DEFAULT', nvl(t.degree,1)),10),
lpad(decode(t.instances, 32767, 'DEFAULT', nvl(t.instances,1)),10),
lpad(decode(bitand(t.flags, 8), 8, 'Y', 'N'),5),
decode(bitand(t.flags, 6), 0, 'ENABLED', 'DISABLED'),
t.samplesize, t.analyzetime,
decode(bitand(t.property, 32), 32, 'YES', 'NO'),
decode(bitand(t.property, 64), 64, 'IOT',
decode(bitand(t.property, 512), 512, 'IOT_OVERFLOW',
decode(bitand(t.flags, 536870912), 536870912, 'IOT_MAPPING', null
))),
decode(bitand(o.flags, 2), 0, 'N', 2, 'Y', 'N'),
decode(bitand(o.flags, 16), 0, 'N', 16, 'Y', 'N'),
decode(bitand(t.property, 8192), 8192, 'YES',
decode(bitand(t.property, 1), 0, 'NO', 'YES')),
decode(bitand(o.flags, 2), 2, 'DEFAULT',
decode(s.cachehint, 0, 'DEFAULT', 1, 'KEEP', 2, 'RECYCLE', NULL)),
decode(bitand(t.flags, 131072), 131072, 'ENABLED', 'DISABLED'),
decode(bitand(t.flags, 512), 0, 'NO', 'YES'),
decode(bitand(t.flags, 256), 0, 'NO', 'YES'),
decode(bitand(o.flags, 2), 0, NULL,
decode(bitand(t.property, 8388608), 8388608,
'SYS$SESSION', 'SYS$TRANSACTION')),
decode(bitand(t.flags, 1024), 1024, 'ENABLED', 'DISABLED'),
decode(bitand(o.flags, 2), 2, 'NO',
decode(bitand(t.property, 2147483648), 2147483648, 'NO',
decode(ksppcv.ksppstvl, 'TRUE', 'YES', 'NO'))),
decode(bitand(t.property, 1024), 0, null, cu.name),
decode(bitand(t.flags, 8388608), 8388608, 'ENABLED', 'DISABLED'),
decode(bitand(t.property, 32), 32, null,
decode(bitand(s.spare1, 2048), 2048, 'ENABLED', 'DISABLED')),
decode(bitand(o.flags, 128), 128, 'YES', 'NO')
from sys.user$ u, sys.ts$ ts, sys.seg$ s, sys.obj$ co, sys.tab$ t, sys.obj$ o,
sys.obj$ cx, sys.user$ cu, x$ksppcv ksppcv, x$ksppi ksppi
where o.owner# = u.user#
and o.obj# = t.obj#
and bitand(t.property, 1) = 0
and bitand(o.flags, 128) = 0
and t.bobj# = co.obj# (+)
and t.ts# = ts.ts#
and t.file# = s.file# (+)
and t.block# = s.block# (+)
and t.ts# = s.ts# (+)
and t.dataobj# = cx.obj# (+)
and cx.owner# = cu.user# (+)
and ksppi.indx = ksppcv.indx
and ksppi.ksppinm = '_dml_monitoring_enabled'

在DBA_TABLES视图中没有太多的限制条件，那么导致DBA_TABLES中没有记录的原因多半出在连接上。

检查一下OBJ$和TAB$表：

SQL> SELECT OBJECT_ID
2 FROM DBA_OBJECTS
3 WHERE OBJECT_NAME = 'ACTION_TABLE';

OBJECT_ID
----------
52449

SQL> SELECT OBJ#, DATAOBJ#, NAME FROM OBJ$ WHERE OBJ# = 52449;

OBJ# DATAOBJ# NAME
---------- ---------- ------------------------------
52449 ACTION_TABLE

SQL> SELECT OBJ#, DATAOBJ#, TS#, BOBJ# FROM TAB$ WHERE OBJ# = 52449;

OBJ# DATAOBJ# TS# BOBJ#
---------- ---------- ---------- ----------
52449 0 52450

当前对象对于的DATAOBJ#为空，说明这个对象没有对应的存储空间，而可以看到这个对象的BOBJ#是52450，查询DBA_OBJECTS视图：

SQL> SELECT OWNER, OBJECT_NAME, OBJECT_ID, DATA_OBJECT_ID, OBJECT_TYPE
2 FROM DBA_OBJECTS
3 WHERE OBJECT_ID IN (52449, 52450);

OWNER OBJECT_NAME OBJECT_ID DATA_OBJECT_ID OBJECT_TYPE
--------------- ------------------------------ ---------- -------------- ------------
OE ACTION_TABLE 52449 TABLE
OE SYS_IOT_OVER_52449 52450 52450 TABLE

显然这个ACTION_TABLE是索引组织表。查询ACTION_TABLE对应的索引信息：

SQL> SELECT OWNER, INDEX_NAME, INDEX_TYPE
2 FROM DBA_INDEXES
3 WHERE TABLE_NAME = 'ACTION_TABLE';

OWNER INDEX_NAME INDEX_TYPE
------------------------------ ------------------------------ ---------------------------
OE ACTION_TABLE_DATA IOT - TOP
OE SYS_IL0000052449C00004$$ LOB

看来ACTION_TABLE不仅是一个索引组织表，还包括LOB对象。而这可能就是前面碰到的ORA-22868错误的原因。

但是现在还有一个疑问，即使是索引组织表，也应该可以在DBA_TABLES视图中可以查询到的。

 

 

 

引用原文：http://yangtingkun.itpub.net/post/468/488288