1. A shiftable memory supporting in-memory data structures comprising: a memory having built-in shifting capability to shift a contiguous subset of the data from a first location to a second location within the memory, the contiguous subset of data having a size that is smaller than a total size of the memory, the built-in shifting capability to shift only data of the contiguous subset; and a data structure defined on the memory to contain data comprising the contiguous subset, the built-in shifting capability to facilitate one or more of movement of the data, insertion of the data and deletion of the data within the data structure, wherein the data structure defined on the memory is located in both of the memory having built-in shifting capability and another, non-shiftable memory.