Error ORA-39064 Might Be Encountered By DataPump Export (EXPDP) When NLS_LANG Is Different From Database Character Set (Doc ID 1321034.1)
在该方案中给出的解决方案是：Please set the character set in environment variable NLS_LANG to database character set.
Oracle Database - Enterprise Edition - Version 10.1.0.2 and later
Information in this document applies to any platform.
***Checked for relevance on 15-Apr-2013***
In a multi-byte character set environment, if the client variable NLS_LANG is set to a character set which is different from database the character set, then DataPump export may encounter errors like:
ORA-39064: unable to write to the log file
ORA-29285: file write error
The Utilities manual specifies:
"Note: Data Pump Export writes the log file using the database character set. If your client NLS_LANG environment setting sets up a different client character set from the database character set, then it is possible that table names may be different in the log file than they are when displayed on the client output screen."
This was investigated in Bug 6136923 (closed as 'Not a Bug') with reference to unpublihsed documentation bug 3174256.
DataPump internally uses the package UTL_FILE and this does not correctly return the characters during NLS conversion.
Please set the character set in environment variable NLS_LANG to database character set.
The following information was added to manual:
Oracle Database PL/SQL Packages and Types Reference
"When data encoded in one character set is read and Globalization Support is told (such as by means of NLS_LANG) that it is encoded in another character set, the result is indeterminate. If NLS_LANG is set, it should be the same as the database character set."