Algorithms and Data Structures · Senior · Question 9 of 75
What can a Bloom filter tell you about a key?
- ✓Correct answer: "Definitely not present" or "maybe present"
- 2"Definitely present" or "maybe absent"
- 3The exact number of times it was inserted
Explanation
It sets k bits per key with k hash functions. If any bit is 0, the key was never added; if all are 1, it might be a false positive. It never gives false negatives and uses a few bits per key, which is why databases use it to skip disk reads.