Initial RFID projects have shown that we need to pay utmost attention to data management. This is due to the enormous data volume that is created by frequent data acquisition processes and increased data granularity. In this paper we focus on the data-on-network approach -- which is preferred by EPCglobal -- and the data-on-tag approach -- which has been neglected by literature. We compare these data management concepts and discuss their possible fields of application. We argue that these methods are not antithetic but complementary, and show how they can be included in an integrated approach.