1. A method of de-duplicating a data volume, the method comprising: generating a sequence of indices based upon respective input data units within the data volume, the sequence of indices including a first index generated based upon a first input data unit of the input data units; reading a pointer value from a storage location within a lookup table indicated by the first index, the pointer value identifying a first sequence of entries within a first dictionary, the first sequence of entries including respective address values that point to respective dictionary data units included in a database of dictionary data units; comparing the address values included within the first sequence of entries with the sequence of indices to produce a scoring value that indicates a likely extent of a match between the dictionary data units and the input data units; if the scoring value exceeds a first threshold, comparing at least one of the dictionary data units pointed to by an entry of the first sequence of entries with the first input data unit; and substituting information representative of the one of the dictionary data units for at least a portion of the first input data unit determined to match a counterpart portion of the one of the dictionary data units.