A STORAGE SYSTEM FOR RANDOMLY NAMED BLOCKS OF DATA

摘要

A method for constructing an index suitable for indexing a large set of records identified by long generally randomly distributed record names, and for answering membership queries about the set, the method comprising adding a new record to the set and assigning the new record a new record name using a process designed to produce names where at least a portion of each name is at least approximately random, determining that the new record name is not already represented in the index by checking a first level index, combining the new record name with record name information already represented in the index to form a combined record name which is shorter than the new record name, adding the combined record name to the first level index to form a new first level index entry that represents the new record, adding a second new record to the set and assigning the second new record a second new record name which :is different than the new record name, determining that the first level index does not contain sufficient information to decide whether or not the second new record name is different than the first new record name, and adding an entry to the first level index that represents the second new record name and that is shorter than the second new record name, wherein the first level index does not contain information sufficient to conclude that the new record name has been added to the index, wherein each different record in the set is assigned a different record name, and wherein at least a portion of the first level index is ordered based on record names.