It is important to be able to retrieve exactly what you are looking for from the stored data. FetchPlans and FetchGroups provide you with a mechanism, where you can specify the retrieval of only those fields that are required from the database, in as few database calls as possible. The other methods of object retrieval including navigation of an object network via object references, retrieving objects by their identifiers and using queries to retrieve objects based on their data values, have been explained, in the previous chapter, Object Retrieval.