Patent ID: 8645664

Claim:
A computing system comprising: a data storage medium; a data storage controller coupled to the data storage medium; a plurality of processes; and a mapping table organized as a plurality of time ordered levels, wherein each level of the plurality of levels comprises one or more mapping table entries, and wherein each of the plurality of entries comprises a tuple including a key that may be used to identify data stored within the system; wherein only a first process of the processes is permitted to modify data corresponding to a first subset of the tuple key values, and only a second process of the processes is permitted to modify data corresponding to a second subset of the tuple key values, wherein the second subset does not overlap the first subset; wherein data corresponding to levels of the time ordered levels which are older than a given time are accessible by both the first process and the second process, wherein said data includes entries corresponding to both the first subset of the tuple key values and the second subset of the tuple key values.