A method for turning variable-length file path names into fixed-length object identifiers in a data repository, the method comprising, assigning a fixed-value identifier to a file system in the data repository, computing a first deterministic pseudo-random function that combines a first component of a plurality of file system pathname components associated with a file with the fixed-value identifier, computing a second deterministic pseudo-random function that combines a second component of the plurality of file system pathname components with the result of the first function, and using at least one of the computed deterministic pseudo-random functions to produce a fixed-length object identifier for the file.