The following is my experience with SSIS building: Make sure you understand the 3 modes of Lookup. General, I would only do full cache if the lookup table only return less than 200 rows Never use the table or view select unless you really need every field on that table or view. select * from a data source will break in the future if more columns are added to the table select * in a lookup brings back unnecessary fields and impact performance Never use "Sort" in SSIS unless it's absolutely necessary. ......