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So it means with a dataset big enough, your bloom filter is virtualy all 1s, and will return true for every values you want to check regardless if it is actually in there ? Is there a threshold you can monitor to avoid this situation ?

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Yes, if a dataset keeps growing, the whole bloom filter will eventually become 1s. If you know the (approximate) expected size of your dataset and the probabilities of false positives you can tolerate, you can calculate how big the filter should be and how many hashing functions you have to use.

I guess there are other techniques to dynamically grow the filter when you need it.

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