Abstract: A method for accessing a stored data base comprising a number of blocks, each of said blocks containing a plurality of data files and a directory with access keys of the files stored in each of the respective blocks, and comprising means for effecting a sorted ordering of the data files such that the access keys in each block have a predetermined relation. Before the data base is accessed the directories of all blocks are read once in a predetermined order to determine the range of access keys in each directory. Thereafter, during each access operation first of all those directories are sorted out (identified) in which, based on the determined ranges of access keys, the search key of the requested data file might be present. Only blocks corresponding to the sorted out directories are then searched for the requested data file.