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A comment on Bloom Filters: More than a space-efficient hashmap. Parent comment

Re:Bloom Filters: More than a space-efficient hashmap by natch on Wednesday August 11, 2021 @02:02AM (#28138582)
Use n copies of the filter staggered in time. Start one on first day/hour/some-time-unit, then on next tick of time unit start a new one. The one started on day 2 lacks the entries from day 1. For checking, only use the oldest one. On the nth day, as you are making yet another one, discard the oldest one and the second oldest one becomes the new oldest one. The oldest one always has n time units of data in it.
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Re:Bloom Filters: More than a space-efficient hashmap by mungoman2 on Wednesday August 11, 2021 @02:16AM (#28138658)
That's clever! You can use this trick to effectively make items expire and be removed after a set time.

But it makes the whole thing more complicated with parameters that need tuning, and no longer the simple and powerful things that bloom filters are sold as.

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