Embodiments of the present invention include a method for performing a data uniqueness check in a set of sorted data blocks comprising accessing data to be inserted into the set of sorted data blocks, determining a proper data block of the set of sorted data blocks for which the data to be inserted should be located based on a first sorting key. The method further includes examining the proper data block for an existing data entry and if the proper data block is empty, the method further includes inserting the data to be inserted into the proper data block of the set of sorted data blocks.