Using larger the BUFFER (such as 10MB, 10,240,000) can improve the speed of EXPORT and IMPORT.
ORACLE will get as much as possible you specify memory size, even if memory is not met, it will not complain. This value is at least the largest and table columns rather Otherwise, the column value will be truncated.
Translator's note :
To be sure , increase BUFFER will greatly improve EXPORT, IMPORT efficiency . ( Ever come across a CASE, increase BUFFER later , IMPORT / EXPORT faster 10 times !)
The author may have made a mistake : " The value in the table and at least the largest column rather , otherwise the column value will be truncated . "
Perhaps the largest of the column is the maximum record size .
About EXPORT / IMPORT optimization , CSDN forum has some concluding postings , such as on BUFFER parameter , COMMIT parameters, etc. , please check .