SSIS OLEDB source read record limits

Hi,

I have created a SSIS package in SQL server 2005.

In one of the package, dataflow task, i have an OLEDB source task which is connected to Oracle database via Native OLEDB\Oracle Provider for OLEDB.

I have written a sql command to read records from one of the table in oracle db. If i preview the count of records, its displays 447,350 records. But when i execute the task it reads 129,636 records from source and load into destination with success and no error.

Can anybody tel me, why does it read less records? is there any limit set for buffer?

Thanks

Bikram