This chapter deals with several important issues pertaining to the management of moving objects datasets in databases. The design of representative benchmarks is closely related to the formal characterization of the properties (that is, distribution, speed, nature of movement) of these datasets; uncertainty is another important aspect that conditions the accuracy of the representation and therefore the confidence in query results; finally, efficient index structures, along with their compatibility with existing softwares, is a crucial requirement for spatio-temporal databases, as it is for any other kind of data.