System design lab
Bloom filter
Add words to a bit array, check membership, and watch false positives appear as it fills.
Each SSTable has one. A key whose bits aren't all set is definitely absent, so the read skips that file. Fill the filter and probe absent names: false positives cost one wasted file read, but a false negative — skipping a file that has the key — can never happen.
Learn the concept
The lesson this lab comes from, with the explanation, a practice task and a quiz.
- Quick read:
- Bloom filters
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