Oracle Export error exp-00091:exporting questionable statistics solution

When you use the EXP tool to export backup or migrate data, sometimes you will report a lot of "exp-00091:exporting questionable statistics" error, the specific phenomenon and processing method please watch ...

1. The phenomenon of problems

[oracle@rh207 exp]$ exp test/test FILE=TEST.DMF log=test.log
...... Ignore......
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
. . Exporting table Snp_txt 6345 rows Exported
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
. . Exporting table SNP_TXT_CROSSR 1019 rows Exported
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00091:exporting questionable statistics.
Exp-00008:oracle Error 1013 encountered
Ora-01013:user requested cancel of current operation
Exp-00056:oracle Error 1403 encountered
...... Ignore......

2. Processing Methods

Specify the Nls_lang environment variable for the Linux system as the data set for the database
1 Query the character set of the database (many methods are used only one)
Sql> Select Userenv (' language ') from dual;

USERENV (' LANGUAGE ')
----------------------------------------------------
American_america. We8iso8859p1

2 Set the Linux operating system Nls_lang environment variables
[oracle@rh207 exp] $export Nls_lang=american_america. We8iso8859p1

The environment variables of the window system are modified by the following methods:
C:\>set Nls_lang=american_america. We8iso8859p1

3. Processing completed,This error is not reported in the EXP export operation