EXP-00091 Exporting questionable statistics.

--EXP-00091 Exporting questionable statistics.
[oracle@ocm1 ~]$ exp userid=scott/tiger tables=t file=/home/oracle/t1.dmp buffer=1048576 log=/home/oracle/t1.log

Export: Release 11.2.0.3.0 - Production on Sat Apr 8 10:22:27 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.


Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Export done in US7ASCII character set and AL16UTF16 NCHAR character set
server uses AL32UTF8 character set (possible charset conversion)

About to export specified tables via Conventional Path ...
. . exporting table                              T          4 rows exported
EXP-00091: Exporting questionable statistics.
Export terminated successfully with warnings.

--查看數據庫字符集
SCOTT@PROD3> select userenv('language') from dual;

USERENV('LANGUAGE')
----------------------------------------------------
AMERICAN_AMERICA.AL32UTF8

[oracle@ocm1 ~]$ export NLS_LANG=AMERICAN_AMERICA.AL32UTF8

--解決
[oracle@ocm1 ~]$ exp userid=scott/tiger tables=t file=/home/oracle/t1.dmp buffer=1048576 log=/home/oracle/t1.log

Export: Release 11.2.0.3.0 - Production on Sat Apr 8 10:23:36 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates.  All rights reserved.


Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
Export done in AL32UTF8 character set and AL16UTF16 NCHAR character set

About to export specified tables via Conventional Path ...
. . exporting table                              T          4 rows exported
Export terminated successfully without warnings.