"exp-00091 exporting questionable statistics"

"exp-00091 exporting questionable statistics"


The precalculated optimizer statistics are flagged as questionable at export time if:

* There are row errors while exporting
* The client character set or NCHAR character set does not match the server character set or
NCHAR character set
* A QUERY clause is specified
* Only certain partitions or subpartitions are exported

If a table is missing the columns specified in the QUERY clause, an error message will be produced, and no rows will be exported for the offending table.

Restrictions
The parameter QUERY cannot be specified for full, user, or tablespace mode exports.
The parameter QUERY must be applicable to all specified tables.
The parameter QUERY cannot be specified in a direct path export (DIRECT=y)
The parameter QUERY cannot be specified for tables with inner nested tables.
You cannot determine from the contents of the export file whether the data is the result of a QUERY export.


Suggestion:
When OS character set different that ORACLE character set then BEFORE export you should set NLS_LANG=.CHARACTERSET according Oracle Database Character set.
Example : Oracle 10gr2 on Linux version 4
OS NLS_LANG = US7ASCII
Oracle NLS_LANG = WE8IS0XXXXX

Just Before export set NLS_LANG like
$export NLS_LANG=.WE8ISOXXXXX
$export your_data

Example on windows

First check "NLS_CHARACTERSET" of database through below query

SQL> select VALUE
2 from nls_database_parameters
3 where PARAMETER = 'NLS_CHARACTERSET';

VALUE
----------------------------------------
WE8MSWIN1252


On command prompt

c:\> set NLS_LANG=.WE8MSWIN1252