Selective materialization of intermediate query results as views is an effective method for improving query performance. In this paper, we extend this technique to adaptively partition views based on the access patterns of a workload. That is, we collect information about the selection conditions of queries at runtime and utilize this information to determine fragment boundaries for the initial partitioning when materializing a view. Furthermore, we refine view partitions over time based on the selection conditions of incoming queries. We present a novel cost-benefit model for partitioned views, as well as a candidate view and fragment selection approach - both of which exploit the nature of partitioned views by taking the correlation among view fragments into account. Furthermore, we present DeepSea, an implementation of these techniques built on top of Hive. Our experimental evaluation demonstrates the effectiveness of partitioned views, improving performance by up to an order of magnitude compared to state-of-the-art approaches.