A method and associated systems improve access time of a federated repository that represents a set of individual data repositories as a virtualized aggregated repository. An analyzer module counts the number of entries in each individual repository that are associated with each possible value of a selected concordance parameter. The analyzer stores these counts in a Concordance Frequency Table. When the federated-repository manager receives a data-access request, the analyzer associates the requested data element with a corresponding value of the concordance parameter. The analyzer then uses information stored in the Table to select an optimal sequence in which the federated-repository manager should search the repositories for the requested data. This optimal sequence orders the repositories such that the first repositories to be searched will be those that contain the greatest number of entries associated with the concordance-parameter value of the requested data.