There is provided an apparatus that includes storage circuitry. The storage circuitry is made up from a plurality of sets, each of the sets having at least one storage location. Receiving circuitry receives an access request that includes an input address. Lookup circuitry obtains a plurality of candidate sets that correspond with an index part of the input address. The lookup circuitry determines a selected storage location from the candidate sets using an access policy. The access policy causes the lookup circuitry to iterate through the candidate sets to attempt to locate an appropriate storage location. The appropriate storage location is accessed in response to the appropriate storage location being found.