1. A method for storing data records within a log data store, the method comprising: generating, by a data processing system, the log data store that stores data records within a plurality of successive non-disjoint layers inserted across a plurality of different types of data storage devices associated with the data processing system; inserting, by the data processing system, a first non-disjoint layer of the plurality of successive non-disjoint layers within a main memory device of the data processing system; inserting, by the data processing system, a set of intermediate non-disjoint layers of the plurality of successive non-disjoint layers within a set of storage-class memory devices of the data processing system; inserting, by the data processing system, a last non-disjoint layer of the plurality of successive non-disjoint layers within a hard disk drive of the data processing system; increasing, by the data processing system, a size of each successive non-disjoint layer in the plurality of successive non-disjoint layers exponentially by a predetermined factor value; and organizing, by the data processing system, the data records into the plurality of successive non-disjoint layers of the log data store inserted across the plurality of different types of data storage devices, wherein each successive non-disjoint layer in the plurality of successive non-disjoint layers includes a set of disjoint sorted lists of data records, and wherein each particular disjoint sorted list of data records in the set of disjoint sorted lists of data records corresponds to a particular key.