You can monitor I/O activity to verify your strategy and determine whether I/O is balanced across fragments.
The onstat -g ppf command displays the number of read-and-write requests sent to each fragment that is currently open. Because a request can trigger multiple I/O operations, these requests do not indicate how many individual disk I/O operations occur, but you can get a good idea of the I/O activity from these columns.
However, the output by itself does not show in which table a fragment is located. To determine the table for the fragment, join the partnum column in the output to the partnum column in the sysfragments system catalog table. The sysfragments table displays the associated table id. To determine the table name for the fragment, join the table id column in sysfragments to the table id column in systables.
Use the partnum field value that you obtain in step 1 in the SELECT statement.
SELECT a.tabname FROM systables a, sysfragments b
WHERE a.tabid = b.tabid
AND partn = partnum_value;