A computer-implemented method includes dividing a data set into a plurality of regions and dividing the plurality of regions into a plurality of chunks of fixed size. The computer-implemented method further includes determining a sample size of the plurality of chunks to be sampled for each region, wherein the sample size is determined based, at least in part, on an acceptance of a likelihood of identifying at least one collision between two regions corresponding to logical entities of a first cluster of logical entities. The computer-implemented method further includes sampling the plurality of chunks for each region based on the determined sample size. The computer-implemented method further includes generating a hash value for each chunk sampled and storing each hash value in an index. The computer-implemented method further includes identifying one or more collisions between the plurality of regions. A corresponding computer system and computer program product are also disclosed.