在我们对Oracle做EXP的过程中,可能会经常遇到EXP-00091 Exporting questionable statistics.的信息,其实它就是exp的error message,它产生的原因是因为我们exp工具所在的环境变量是的NLS LANG中的NLS_CHARCATERSET不一致引起的。但需要说明的是,EXP-00091这个error对所生成的dump文件没有影响,生成的dump文件还可以正常imp。
下面我们来解决这个问题,让其不再出现:
第一步:
查看DB中的NLS_CHARACTERSET的值(提供两种方法):
查询NLS_CHARACTERSET的值:
select * from nls_database_parameters t where t.parameter='NLS_CHARACTERSET'
or
select * from v$nls_parameters where parameter='NLS_CHARACTERSET';
SQL> select * from v$nls_parameters where parameter='NLS_CHARACTERSET';
PARAMETER VALUE
----------------------- ----------------------------------------------
NLS_CHARACTERSET ZHT16BIG5
第二步:
根据第一步查出的NLS_CHARACTERSET(ZHT16BIG5)来设定exp的环境变量:
WINNT> set NLS_LANG=AMERICAN_AMERICA.ZHT16BIG5
进行设定后,在环境变量中查看NLS_LANG的值是否一致,如果不一致可在环境变量中手中修改。
LINUX> export NLS_LANG=AMERICAN_AMERICA.ZHT16BIG5
附上exp-00091的oracle error message 解決方案说明:
error exp 91
00091, 00000, "Exporting questionable statistics."
// *Cause: Export was able export statistics, but the statistics may not be
// usuable. The statistics are questionable because one or more of
// the following happened during export: a row error occurred, client
// character set or NCHARSET does not match with the server, a query
// clause was specified on export, only certain partitions or
// subpartitions were exported, or a fatal error occurred while
// processing a table.
// *Action: To export non-questionable statistics, change the client character
// set or NCHARSET to match the server, export with no query clause,
// export complete tables. If desired, import parameters can be
// supplied so that only non-questionable statistics will be imported,
// and all questionable statistics will be recalculated.