Re:Handling five billion sessions a day in real time
by MrBuddyCasino on Friday February 20, 2015 @09:16AM
(#9080466)
I had a hunch I'd see the data structures du jour in there: Bloom Filters and HyperLogLog. Since they are pretty accurate by themselves already but run much faster than the brute force approach, why keep the latter? The error margin, if used properly, should be small enough so people shouldn't really care.
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Re:Handling five billion sessions a day in real time
by ropiku on Friday February 20, 2015 @09:34AM
(#9080543)
They are not for accuracy. One usage for instance is to recompute stats if there are bugs in the stats processing code. Or if you want to add more metrics. (I work at Twitter but not on Answers).