Specifies the type of database optimizer statistics to generate when the exported data is imported. Options are
In some cases, Export will place the precalculated statistics in the export file, and also the
ANALYZE statements to regenerate the statistics.
However, the precalculated optimizer statistics will not be used at export time if a table has columns with system-generated names.
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
QUERY clause is specified
Only certain partitions or subpartitions are exported
ROWS=n does not preclude saving the precalculated statistics in the export file. This enables you to tune plan generation for queries in a nonproduction database using statistics from a production database.