The proliferation of imprecise data has motivated both researchers and the database industry to push statistical techniques into relational database management systems (RDBMSs). We study algorithms to maintain model-based views for a popular statistical technique, classification, inside an RDBMS in the presence of updates to the training examples. We make three technical contributions: (1) An algorithm that incrementally maintains classification inside an RDBMS. (2) An analysis of the above algorithm that shows that our algorithm is optimal among all deterministic algorithms (and asymptotically within a factor of 2 of a nondeterministic optimal). (3) An index structure based on the technical ideas that underlie the above algorithm which allows us to store only a fraction of the entities in memory. We apply our techniques to text processing, and we demonstrate that our algorithms provide several orders of magnitude improvement over non-incremental approaches to classification on a variety of data sets: such as the Cora, UCI Machine Learning Repository data sets, Citeseer, and DBLife.