  In this paper, we propose a schema optimization method for time-dependent
workloads for NoSQL databases. In our proposed method, we migrate schema
according to changing workloads, and the estimated cost of execution and
migration are formulated and minimized as a single integer linear programming
problem. Furthermore, we propose a method to reduce the number of optimization
candidates by iterating over the time dimension abstraction and optimizing the
workload while updating constraints.
