DICTIONARY FOR DATA DEDUPLICATION

Mechanisms are provided for efficiently improving a dictionary used for data deduplication. Dictionaries are used to hold hash key and location pairs for deduplicated data. Strong hash keys prevent collisions but weak hash keys are more computation and storage efficient. Mechanisms are provided to use both a weak hash key and a strong hash key. Weak hash keys and corresponding location pairs are stored in an improved dictionary while strong hash keys are maintained with the deduplicated data itself. The need for having uniqueness from a strong hash function is balanced with the deduplication dictionary space savings from a weak hash function.