You can use the QUERY parameter to help you. The QUERY parameter is a WHERE clause appended to the SELECT statement which pulls data out of all tables being exported. So if multiple tables are being exported, the WHERE clause will be applied to each table in the export dump. For example, consider the following:
exp userid=scott/tiger file=my_dump.dmp tables=dept,emp query='WHERE deptno=10'
In the above example, only those rows where DEPTNO=10 will be exported from the EMP and DEPT tables.
For more information on the exp utility, have a look at the Oracle docs where these parameters are described in more detail.
This was first published in August 2007