What is the data source (e.g. oracle, SQL server, DB2, etc)?

If SQL Server, consider using the ROW_NUMBER () function in a CTE to select e.g. 100.000 records at a time.

use variables, e.g. StartAt and UpTo (both of datatype (DT_I8)) to identify which row numbers to use.

also remember to sort.

refer to the following link: http://msdn.microsoft.com/en-us/library/ms186734.aspx