在前面的文章中已经找到了问题的解决方法，而且在上一篇的文章中已经推测出了导致问题的大致原因。

这里要根据前面推测的原因尝试重现问题，来最终确定导致文件的原因。

在10.2版本的数据库中，模仿当时的操作，利用IMP方式导入索引，检查是否能够重现这个问题。

SQL> create table t_stat (id number, name varchar2(30))
  2  partition by range (id)
  3  (partition p1 values less than (10000),
  4  partition p2 values less than (20000),
  5  partition p3 values less than (maxvalue));

Table created.

SQL> insert into t_stat
  2  select rownum, object_name
  3  from dba_objects;

70959 rows created.

SQL> commit;

Commit complete.

SQL> host
[oracle@yans1 ~]$ imp test/test file=t_stat.dmp ignore=y tables=t_stat

Import: Release 10.2.0.3.0 - Production on 星期二 9月 8 15:19:10 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in ZHS16GBK character set and AL16UTF16 NCHAR character set
. importing TEST's objects into TEST
. importing TEST's objects into TEST
Import terminated successfully without warnings.
[oracle@yans1 ~]$ exit
exit

SQL> select table_name, index_name
  2  from user_indexes
  3  where table_name = 'T_STAT';

TABLE_NAME                     INDEX_NAME
------------------------------ ------------------------------
T_STAT                         IND_T_STAT_ID

SQL> exec dbms_stats.gather_table_stats(user, 'T_STAT')

PL/SQL procedure successfully completed.

模仿当时的情况，创建了一个分区表，并利用exp的逻辑备份建立索引。通过imp导入后发现，问题并没有重新，下面指定rows=n的方式再次执行导入：

SQL> drop index ind_t_stat_id;

Index dropped.

SQL> host
[oracle@yans1 ~]$ imp test/test file=t_stat.dmp ignore=y tables=t_stat rows=n

Import: Release 10.2.0.3.0 - Production on 星期二 9月 8 15:20:11 2009

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

Export file created by EXPORT:V10.02.01 via conventional path
import done in ZHS16GBK character set and AL16UTF16 NCHAR character set
. importing TEST's objects into TEST
. importing TEST's objects into TEST
Import terminated successfully without warnings.
[oracle@yans1 ~]$ exit
exit

SQL> select table_name, index_name
  2  from user_indexes
  3  where table_name = 'T_STAT';

TABLE_NAME                     INDEX_NAME
------------------------------ ------------------------------
T_STAT                         IND_T_STAT_ID

SQL> exec dbms_stats.gather_table_stats(user, 'T_STAT')
BEGIN dbms_stats.gather_table_stats(user, 'T_STAT'); END;

*
ERROR at line 1:
ORA-20005: object statistics are locked (stattype = ALL)
ORA-06512: at "SYS.DBMS_STATS", line 13182
ORA-06512: at "SYS.DBMS_STATS", line 13202
ORA-06512: at line 1

这次问题重现了，现在可以确定，问题就是由于导入的时候指定了rows=n，而使得表的统计信息被锁定。

下面检查表的分析情况：

SQL> alter session set nls_date_format = 'yyyy-mm-dd hh24:mi:ss';

Session altered.

SQL> select table_name, last_analyzed        
  2  from user_tables
  3  where table_name = 'T_STAT';

TABLE_NAME                     LAST_ANALYZED
------------------------------ -------------------
T_STAT                         2009-09-08 15:20:11

下面分析当前的SCHEMA，检查这个对象是否会被跳过：

SQL> exec dbms_stats.gather_schema_stats(user)

PL/SQL procedure successfully completed.

SQL> select table_name, last_analyzed
  2  from user_tables
  3  where table_name like 'T_S%';

TABLE_NAME                     LAST_ANALYZED
------------------------------ -------------------
TEST                           2009-09-08 15:48:59
T_STAT                         2009-09-08 15:20:11

SQL> select sysdate from dual;

SYSDATE
-------------------
2009-09-08 15:49:37

当表T_STAT的统计信息被锁定，收集当前SCHEMA的统计信息时，会跳过这个表的统计信息，这与前面碰到的现在完全一致。

至此确定了导致问题的真正原因。