efficient / cuckoofilter

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Aboun “delete item” #46

Open 936187425 opened 1 year ago

936187425 commented 1 year ago

I see your note that deleting item is sure that the deleted item must be the filter. May I ask if the principle of a cuckoo filter requires the deleted element to be included in the filter when deleting elements?

burdges commented 1 year ago

It depends upon usage, but I think cuckoofilters typically preserve the whole original key inside the entry, with which they avoids removing a collision. In principle, you only need derived key parts, so then remove risks removing a collision incorrectly, due to hash collisions. I doubt anyone uses cryptographic hashes, like 128 or really 256 bits, but those avoid collisions without storing the original key of course.