1、环境介绍
操作系统:Red Hat Enterprise Linux Server release 7.9 数据库: Oracle 11.2.0.4.0
2、问题描述
在对一张数据表进行move table方式收缩空间时,遇到ORA-00600: internal error code, arguments: [25027], [7], [0] 的错误,导致收缩失败。
该表非分区表,不涉及lob类型的字段。后续排查发现,是由于该表存在虚拟索引(采用NOSEGMENT选项创建)导致,删除该索引后,move table 成功。 参考文档:ORA-600 [25027] (文档 ID 284433.1)
3、分析及处理过程
1) 模拟报错详情
ALTER TABLE USER.TABLE1 move parallel 8 nologging
ERROR at line 1:
ORA-00600: internal error code,arguments:[25027],[7],[0],[],[],[],[],
[],[],[],[],[]
2) 分析过程
开始怀疑为move table 语句的问题,故再次检查了有无分区,lob字段信息
检查是否为分区表
select table_owner,table_name, partition_name, tablespace_name from dba_tab_partitions where table_owner='USER' and table_name='TABLE1';
no rows selected
检查是否包含lob类型字段
select distinct DATA_TYPE from dba_tab_columns where owner='USER' and table_name='TABLE1';
DATA TYPE
-----------
CHAR
NUMBER
DATE
VARCHAR2
3) 查阅MOS文档
根据MOS文档284433.1中描述
以ORA-00600: internal error code, arguments: [25027], [7], [0], [], [], [], [], 为例 其中[25027] 后面的每个值都有不同的含义
第一个参数:代表表空间编号 第二个参数:十进制所对应的数据块地址
在12c数据库中,还包含多租户信息 第一个参数:0代表没有启用多租户,1代表root pdb,其它则对应具体PDBID 第二个参数:PDBID 第三个参数:代表表空间编号 第四个参数:十进制所对应的数据块地址
SUGGESTIONS:
1. If the Arg [b] or [d] in 12c (the RDBA) is 0 (zero), then this could be caused by fake indexes. The following query will list fake indexes:
select do.owner,do.object_name, do.object_type,sysind.flags
from dba_objects do, sys.ind$ sysind
where do.object_id = sysind.obj#
and bitand(sysind.flags,4096)=4096;
If the above query returns any rows, check the objects involved and consider dropping them as they can cause this error.
or it could be the case described in the next article when allocating a block for a LOB segment in a DML:
Note 1608861.1 ORA-00600 [25027] [x] [0]
2. Run analyze table validate structure on the table referenced in the Current SQL statement in
the related trace file.
If the Known Issues section below does not help in terms of identifying
a solution, please submit the trace files and alert.log to Oracle
Support Services for further analysis.
针对该错误提供的建议,其特别说明了第二个参数为0 的情况,与现有故障相符合。 如果第二个参数为0或者12c中第四个参数为0,其可能由伪索引引起,并提供了相应查询语句。
查询是否包含相关索引

4) 后续处理
经沟通确认,上述查询出的索引为之前进行sql优化时,创建的虚拟索引。 根据建议,删除这两个索引即可。
drop index "USER"."INDEX1"; drop index "USER"."INDEX2";
后续可正常进行move table操作,不再提示ORA-600相关错误。
5)虚拟索引使用场景
虚拟索引是定义在数据字典中的伪索引,但没有相关的索引段。虚拟索引的目的是模拟索引的存--而不用真实的创建一个完整索引。这允许开发者创建虚拟索引来查看相关执行计划而不用等到真实创建完索引才能查看索引对执行计划的影响,并且不会增加存储空间的使用。如果我们观察到优化器生成了一个昂贵的执行计划并且SQL调整指导建议我们对某些的某列创建索引,但在生产数据库环境中创建索引与测试并不总是可以操作。我们需要确保创建的索引将不会对数据库中的其它查询产生负面影响,因此可以使用虚拟索引。
举例说明
创建测试表t1
SQL> create table t1 as select * from dba_objects;
Table created.
SQL> desc t1;
Name Null? Type
----------------------------------------- -------- ----------------------------
OWNER VARCHAR2(30)
OBJECT_NAME VARCHAR2(128)
SUBOBJECT_NAME VARCHAR2(30)
OBJECT_ID NUMBER
DATA_OBJECT_ID NUMBER
OBJECT_TYPE VARCHAR2(19)
CREATED DATE
LAST_DDL_TIME DATE
TIMESTAMP VARCHAR2(19)
STATUS VARCHAR2(7)
TEMPORARY VARCHAR2(1)
GENERATED VARCHAR2(1)
SECONDARY VARCHAR2(1)
NAMESPACE NUMBER
EDITION_NAME VARCHAR2(30)
查询SUBOBJECT_NAME =WRH$_IC_PINGS_MXDB_MXSN记录
SQL> col OWNER for a10
SQL> col OBJECT_NAME for a10
SQL> col SUBOBJECT_NAME for a10
SQL> select * from t1 where SUBOBJECT_NAME ='WRH$_IC_PINGS_MXDB_MXSN';
OWNER OBJECT_NAM SUBOBJECT_ OBJECT_ID DATA_OBJECT_ID OBJECT_TYPE CREATED LAST_DDL_ TIMESTAMP STATUS T G S NAMESPACE EDITION_NAME
---------- ---------- ---------- ---------- -------------- ------------------- --------- --------- ------------------- ------- - - - ---------- ------------------------------
SYS WRH$_INTER WRH$_IC_PI 6676 87215 TABLE PARTITION 24-AUG-13 24-AUG-13 2013-08-24:12:07:18 VALID N N N 1
CONNECT_PI NGS_MXDB_M
NGS XSN
SYS WRH$_INTER WRH$_IC_PI 87216 87216 INDEX PARTITION 24-AUG-13 24-AUG-13 2013-08-24:12:07:41 VALID N N N 4
CONNECT_PI NGS_MXDB_M
NGS_PK XSN
查看执行计划
SQL> set autot traceonly
SQL> select * from t1 where SUBOBJECT_NAME ='WRH$_IC_PINGS_MXDB_MXSN';
Execution Plan
----------------------------------------------------------
Plan hash value: 3617692013
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 2898 | 344 (1)| 00:00:05 |
|* 1 | TABLE ACCESS FULL| T1 | 14 | 2898 | 344 (1)| 00:00:05 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("SUBOBJECT_NAME"='WRH$_IC_PINGS_MXDB_MXSN')
Note
-----
- dynamic sampling used for this statement (level=2)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
1239 consistent gets
0 physical reads
0 redo size
1843 bytes sent via SQL*Net to client
523 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed
SQL> set autot off
因为SUBOBJECT_NAME没有索引,只能使用全表扫的方式
创建虚拟索引
SQL> create index ind_t1_subobj on t1(SUBOBJECT_NAME) nosegment;
Index created.
使用nosegment方式创建所以不会分配索引段,但是在数据字典里面存在索引对象。
SQL> select index_name from dba_indexes where table_name = 'T1' and index_name ='ind_t1_subobj';
no rows selected
SQL> select object_name,object_type from dba_objects where object_name = upper('ind_t1_subobj');
OBJECT_NAME OBJECT_TYPE
---------------------------------------- -------------------
IND_T1_SUBOBJ INDEX
重新执行语句
SQL> alter session set "_use_nosegment_indexes"=true;
Session altered.
SQL> set autot traceonly
SQL> select * from t1 where SUBOBJECT_NAME ='WRH$_IC_PINGS_MXDB_MXSN';
Execution Plan
----------------------------------------------------------
Plan hash value: 4031138016
---------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
---------------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 2898 | 5 (0)| 00:00:01 |
| 1 | TABLE ACCESS BY INDEX ROWID| T1 | 14 | 2898 | 5 (0)| 00:00:01 |
|* 2 | INDEX RANGE SCAN | IND_T1_SUBOBJ | 393 | | 1 (0)| 00:00:01 |
---------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("SUBOBJECT_NAME"='WRH$_IC_PINGS_MXDB_MXSN')
Note
-----
- dynamic sampling used for this statement (level=2)
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
1239 consistent gets
0 physical reads
0 redo size
1843 bytes sent via SQL*Net to client
523 bytes received via SQL*Net from client
2 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
2 rows processed
SQL> set autot off
发现使用了索引范围扫。
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