In an example, an analytic function to be performed on data stored in an input block is managed through an interface to a framework through which a user is to define the analytic function. The framework is to buffer batches of the data into a memory through implementation of a Reader, a Writer, a PreReader, and a PreWriter on the data stored in the input block when the user-defined analytic function is performed, and wherein the Reader, the Writer, the PreReader, and the PreWriter are individually movable with respect to each other in the input block. In addition, the user-defined analytic function is received through the interface.