1. A computer-implemented method for preparing sparse data for retrieval by a client, the method comprising: receiving a current sparse track fragment; identifying a previous sparse track fragment received prior to the current sparse track fragment; storing a reference to the identified previous sparse track fragment in association with the received current sparse track fragment; identifying a current continuous track fragment associated with the current sparse track fragment; storing a reference to the received current sparse track fragment in association with the identified current continuous track fragment; and providing the identified current continuous track fragment including the stored reference to the received current sparse track fragment to at least one client, wherein the preceding steps are performed by at least one processor.