一.一個9I的庫EXP時出現EXP-00091錯誤
[oracle@localhost tmp]$ exp "'/ as sysdba'" tables=testxuchao.TAB_XN_PY_DICT \
> file=/tmp/xifenfei.dmp log=/tmp/xifenfei.log
Export: Release 9.2.0.4.0 - Production on Mon Jan 16 16:02:37 2012
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
Export done in US7ASCII character set and AL16UTF16 NCHAR character set
server uses ZHS16GBK character set (possible charset conversion)
About to export specified tables via Conventional Path ...
Current user changed to TESTXUCHAO
. . exporting table TAB_XN_PY_DICT 25433 rows exported
EXP-00091: Exporting questionable statistics.
EXP-00091: Exporting questionable statistics.
Export terminated successfully with warnings.
分析：當環境變量和數據庫的不一致，在導出統計信息時候，會報EXP-00091錯誤。
二.查看NLS相關參數
[oracle@localhost tmp]$ echo $NLS_LANG
AMERICAN
SQL> col value for a30
SQL> select parameter,value from nls_database_parameters
2 where parameter like '%CHARACTERSET%';
PARAMETER VALUE
------------------------------ ------------------------------
NLS_CHARACTERSET ZHS16GBK
NLS_NCHAR_CHARACTERSET AL16UTF16
三.解決方法
1.設置NLS_LANG爲NLS_CHARACTERSET
[oracle@localhost tmp]export NLS_LANG=american_america.ZHS16GBK
[oracle@localhost tmp]$ exp "'/ as sysdba'" tables=testxuchao.TAB_XN_PY_DICT \
> file=/tmp/xifenfei.dmp log=/tmp/xifenfei.log
Export: Release 9.2.0.4.0 - Production on Mon Jan 16 16:08:10 2012
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
Export done in ZHS16GBK character set and AL16UTF16 NCHAR character set
About to export specified tables via Conventional Path ...
Current user changed to TESTXUCHAO
. . exporting table TAB_XN_PY_DICT 25433 rows exported
Export terminated successfully without warnings.
2.使用statistics=none
[oracle@localhost tmp]$ exp "'/ as sysdba'" tables=testxuchao.TAB_XN_PY_DICT \
> file=/tmp/xifenfei.dmp log=/tmp/xifenfei.log statistics=none
Export: Release 9.2.0.4.0 - Production on Mon Jan 16 16:08:53 2012
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
Export done in US7ASCII character set and AL16UTF16 NCHAR character set
server uses ZHS16GBK character set (possible charset conversion)
About to export specified tables via Conventional Path ...
Current user changed to TESTXUCHAO
. . exporting table TAB_XN_PY_DICT 25433 rows exported
注意：這個問題主要是出現在低數據庫版本9I 的EXP/IMP上，從ORACLE 10G開始，EXPDP/IMPDP可以自動轉換字符集和環境變量，當然，如果從高版本導入數據至低版本，如11G導入10G，EXPDP/IMPDP這種方式仍需加入version參數進行轉換。
