在使用EXP工具进行导出备份或迁移数据的时候有时会报很多的“EXP-00091: Exporting questionable statistics”错误，具体的现象和处理方法请观看……1.问题现象[oracle@RH207 exp]$ exp test/test file=test.dmf log=test.log……忽略……EXP-00091: Exporting questionable statistics.EXP-00091: Exporting questionable statistics.EXP-00091: Exporting questionable statistics.. . exporting table SNP_TXT 6345 rows exportedEXP-00091: Exporting questionable statistics.EXP-00091: Exporting questionable statistics.EXP-00091: Exporting questionable statistics.. . exporting table SNP_TXT_CROSSR 1019 rows exportedEXP-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 encounteredORA-01013: user requested cancel of current operationEXP-00056: ORACLE error 1403 encountered……忽略……2.处理方法指定Linux系统的NLS_LANG环境变量为数据库的数据集1）查询数据库的字符集（方法很多只用一种）SQL> select userenv('language') from dual;USERENV('LANGUAGE')----------------------------------------------------AMERICAN_AMERICA.WE8ISO8859P12）设置Linux操作系统的NLS_LANG环境变量[oracle@RH207 exp]$export NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P1Window系统的环境变量的修改方法是：C:/>set NLS_LANG=AMERICAN_AMERICA.WE8ISO8859P13.OK，处理完成，在进行EXP导出操作就不会报这个错误了
