Abstract: Exemplary methods, computer systems, and computer program products for efficient destaging of a write ahead data set (WADS) track in a volume of a computing storage environment are provided. In one embodiment, the computer environment is configured for preventing destage of a plurality of tracks in cache selected for writing to a storage device. For a track N in a stride Z of the selected plurality of tracks, if the track N is a first WADS track in the stride Z, clearing at least one temporal bit for each track in the cache for the stride Z minus 2 (Z?2), and if the track N is a sequential track, clearing the at least one temporal bit for the track N minus a variable X (N?X).

Abstract: Systems and methods for verifying membership in one or more sets that are subsets of a global set are provided. The method compromises representing members of the global set by mapping each member to a distinct Boolean variable of length d, wherein 2d is not less than the number of members in the global set; representing each of the given subsets of the global set by a Boolean expression which evaluates to a first value for any of the assignments to the Boolean variables which represent members of the subset, and which evaluates to a second value for any of the assignments to the Boolean variables which represent members of the global set that are not members of the subset.